# How To: Anesthetize Feeder Insects



## Stylopidae (Dec 27, 2007)

Fruit flies are desireable feeders for many keepers. However, due to their very mobile nature they are also extremely difficult to use. This goes for many different species of roaches, as well...namely lobster roaches, which were the test subjects I used for this experiment.

The main method here is to use Carbon Dioxide. Previously, I had used dry ice...however, this raises a multitude of problems for the casual hobbiest. It's somewhat difficult to handle safely and it doesn't store very well.

However, this can be overcome with some relatively simple chemistry.

Sodium bicarbonate releases carbon dioxide whenever it reacts with an organic acid. Most cola products also contain dissolved CO2.

In this paper, I used Alka-Seltzer, Vinegar and Baking Soda and half a can of Vanilla Coke to knock out lobster roaches (because I didn't have any fruit flies handy).

First, what you need is an airtight reaction vessel. Believe it or not, soda bottles and waterbottles are already airtight, even after they're open.

I made three initial prototypes and eventually settled on this one:







This was made from a water bottle with a lift-nozzle (gatorade bottles have this type of nozzle). I prefer this type because it seals the CO2 from the reaction in and keeps the contents of the reaction under pressure until it's needed.

You will also need one of these:







To make the chamber, simply glue the nozzle around the hole of the waterbottle's nozzle type thing. The seal doesn't neccessarily have to be airtight (acheiving an airtight seal with hot glue is harder than one thinks), it just has to be sturdy.

Second, attach aquarium tubing to the top of the bottle like so:







Now, you have a complete reaction vessel.

Next, you need a way to get CO2. As mentioned earlier, I used alka-seltzer:







Vinegar and Baking Soda:







And about half a can of Vanilla Coke:







I acheived identical results with all 3 methods, however Alka-Seltzer was the one I found easiest to use because controlling the beginning of the reaction was easiest with this method. Because I was able to start the reaction immediately before capping the bottle, this method captured the most CO2.

Vinegar and Baking soda is the most economical route to go, though. I picked up a 1 liter bottle of vinegar and a pound of baking soda for about $1.20. I picked up a package of 36 equate tablets for $1.57.







The tablets come two to a package, although you could probably get away with using one tablet per session.







First off, you need to get the tablets in the bottle:







The tablets aren't going to fit into most water bottles, so breaking them up is OK.







In fact, breaking the tablets into fourths increases their surface area and speeds the reaction up.

For the purposes of documentation, I reversed the steps. I reccomend filling the bottle 1/4th full of water, and then putting the tablets in.

Cap the bottle as soon as possible and let the reaction build pressure in the bottle.

Now...like I said earlier, this is designed around fruit flies but can be used for other species...roaches, wasps, baby tarantulas that just won't co-operate.

To simulate the vials the fruit flies come in when you buy them, I simply used a cleaned out old vial I had lying around for this experiment.

In that vial, I used three sizes of roaches. 1st instar, 3rd or 4th instar and an adult.







Here's the video of them being knocked out...just so you can see how fast this really works:



To prove this doesn't kill them outright, I also filmed their recovery:



Ignore my estimates for their size in this video. They're incorrect because I filmed this sometime between 2 and 3 in the morning so I was really tired. The roach medium roach is roughly half grown...which would most likely put it around the 4th instar.

In fact, I referr to the three sizes as 'instars' when I meant to say 'small', 'medium' and 'large'.

Stupid mistake.

Anyways...this method can cut your feeding times by about half. Simply collect some fruit flies, crickets, or roaches, knock them out and then put them into your spider's enclosure. They'll come to after a few minutes and as a bonus will still be a bit 'groggy' when the spider finally finds them which decreases the chance for injury.

Also, CO2 anesthetization has been used to cancel the diapause period in mated wasp foundresses and bumblebee queens...so this could very well be used to simulate hibernation without the need to put them through a relatively risky hibernation period in a refridgerator.

The wasp thing is what got me interested in researching these methods, although I think this will find wider use among hobbiests with use on feeder insects.

I would like to say this to all the wasp keepers on AB, though...I have had an amazing time over the past two years working with these magnifficent creatures. Before I started working with wasps, I never would have imagined I would have had so much fun working with insects.

I have met some truly incredible people through doing this and have had a lot of fun and have overcome some pretty major challenges while working on these caresheets.

Unfortunately, my path as a hobbiest is currently drawing me away from that hobby. As fun as it is, it is very time consuming and there are projects which I would like to work on that will demand more and more of my time and because of that, I don't think I'll be able to care for a full fledged wasp colony this year or until my other projects are complete.

I am taking a break from that hobby and will not be publishing any more articles on their care for at least two years.

Instead, I ask everyone who works with wasps to keep working and refining the methods and to pick up where I have left off and to keep documenting everything you have done. I'll probably return to that hobby in a year or two and by that time, I want to see people actually breeding these guys in captivity.


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## Bigboy (Dec 27, 2007)

Ever toy with making a euthanasia chamber for feeder rodents?


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## Stylopidae (Dec 27, 2007)

Bigboy said:


> Ever toy with making a euthanasia chamber for feeder rodents?


I'm currently working on a chamber designed for adult tarantulas and centipedes that uses a CO2 tank. I guess when completed, the larger version could be used for that.

To euthanize feeder rodents, I'm more of a fan of snapping their neck at the skull. I believe it to be more humane than CO2.

Interestingly enough...this project has turned out much harder than I thought.

My first attempt resulted in a rubbermaid jar being blown across the room, the second attempt resulted in a blown hose and the third attempt resulted in a lobster roach disintigrating like a suicide bomber.


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## Truff135 (Dec 27, 2007)

Do you wear any protective gear for these experiments (which I find fascinating by the way  ).  I just don't think I'd want a jar/bottle/etc of any kind flying across any room that has me in it.


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## Xaranx (Dec 27, 2007)

Pretty neat stuff.  If I ever need to use fruit flies I might see what I can jerry rig for cheap.  What went wrong that caused the roach to disintegrate?  So I know what not to do.


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## Truff135 (Dec 27, 2007)

Xaranx said:


> Pretty neat stuff.  If I ever need to use fruit flies I might see what I can jerry rig for cheap.  What went wrong that caused the roach to disintegrate?  So I know what not to do.


I don't think it was the first experiment, it sounds like it was the second one designed for larger creatures, where he used the freakin' CO2 *TANK *lol...man, that sounds like fun.  Not blowing up roaches, I mean just tampering and fiddling with stuff.


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## Stylopidae (Dec 27, 2007)

Truff135 said:


> Do you wear any protective gear for these experiments (which I find fascinating by the way  ).  I just don't think I'd want a jar/bottle/etc of any kind flying across any room that has me in it.


None is required. My other project (not this one) is a larger version of this using a high pressure CO2 tank and I'm having trouble getting the pressure down past 80 PSI or so. I use saftey goggles and gloves for that project.

This project just uses chemical reactions to produce small amounts of CO2.

For the project described in the above article, you need no more protective equipment than you would with an overly shaken up pop bottle.



Xaranx said:


> Pretty neat stuff.  If I ever need to use fruit flies I might see what I can jerry rig for cheap.  What went wrong that caused the roach to disintegrate?  So I know what not to do.


I connected the tank to a bottle and turned the CO2 on. There was a 'smoke' type substance and I lost control of the CO2 flow. When I turned the CO2 off, I dropped the rubbermade jar I was using which caused it to shatter.

If you've ever shot an empty paintball gun at a bug, I think it was the same concept.

Again...that did _not_ happen while I was working with *this* project. That happened on a different one.


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## xhexdx (Dec 27, 2007)

Very interesting...I was under the impression CO2 would kill them.  Guess I was wrong!

So wouldn't it be easier to toss them in the fridge?  I realize it would take a bit longer for them to slow down, but I would think it might be cheaper and you wouldn't be dealing with contents under pressure. 

Great article though!


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## Truff135 (Dec 27, 2007)

Cheshire said:


> None is required. My other project (not this one) is a larger version of this using a high pressure CO2 tank and I'm having trouble getting the pressure down past 80 PSI or so. I use saftey goggles and gloves for that project.
> 
> This project just uses chemical reactions to produce small amounts of CO2.
> 
> For the project described in the above article, you need no more protective equipment than you would with an overly shaken up pop bottle.


Clearly, you have never seen me with a shaken-up pop bottle.  Dangerous, I tell ya!!!   
Just kidding, of course.

For the bigger experiments though, goggles was basically what I had in mind (or possibly head-gear, should an errant bottle/tank fly dangerously close to your head haha [j/k]).  I figured you would take that into consideration, though.


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## Stylopidae (Dec 27, 2007)

xhexdx said:


> Very interesting...I was under the impression CO2 would kill them.  Guess I was wrong!
> 
> So wouldn't it be easier to toss them in the fridge?  I realize it would take a bit longer for them to slow down, but I would think it might be cheaper and you wouldn't be dealing with contents under pressure.
> 
> Great article though!


Nope...CO2 merely knocks them out for awhile unless you leave them in the CO2 overnight in an airtight container.

Tossing them in the fridge may be easier for some, but it takes longer. This immobilizes them in under 10 seconds and they take a lot longer to recover from the CO2 than they do to warm back up. Furthermore, when they do recover they pretty much pop right back.

The pressure really isn't all that much, either. I made a version of this container (also from a modified pop bottle...a coke bottle to be exact) that wasn't able to hold the pressure and it worked just as well but at the same time it wasn't able to store the CO2. If used, the chemicals would have to be mixed immediately and used immediately. If you'd like, just let me know and I can post the instructions later tonight.

Besides most folks have alka-seltzer, vinegar and baking soda in their house already. This requires only a nozzle which you can attach aquarium tubing to and a plastic bottle on top of that.

A friend also told me that it may be possible to use warm water, yeast and sugar.


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## Brian S (Dec 27, 2007)

Just what else are you "cooking" in chem class, Joe? LOLOL

Sorry for the off topic banter, I just had a weak moment


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## singlemind (Dec 27, 2007)

For larger stuff, if you ever do use the tank... make sure you just have space for the excess to escape. 'round these parts we just use 5 gallon buckets with a hose to the co2 tank, mostly for rodents. I suppose you could try packing tape along the sides to prevent your roaches from climbing out. even with the bucket top off, co2 is a bit heavier (i'm pretty sure, seems to be anyways) Something tells me I'm going to be experimenting with this tonight. 

Otherwise, I've used ether before for anesthesia for fruit flies, lasts a few seconds.. but then, ether isn't something you really want around either.


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## JColt (Dec 27, 2007)

Cheshire said:


> My first attempt resulted in a rubbermaid jar being blown across the room, the second attempt resulted in a blown hose and the third attempt resulted in a lobster roach disintigrating like a suicide bomber.


 Sounds like one of my type of projects


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## lucanidae (Dec 27, 2007)

Haha, or you could just stick them in the fridge.



> I'm currently working on a chamber designed for adult tarantulas and centipedes that uses a CO2 tank. I guess when completed, the larger version could be used for that.


You don't need a chamber. Just hook the tank up to a quarter inch plastic tube and aim a low stream on them. Aiming towards the book lungs on larger spiders makes it work faster.


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## matthias (Dec 27, 2007)

fascinating!

If you gave them more CO2 would they stay out longer? Any problems with repeated exposures?

I thinking this could save time feeding a few spiders but what about 50 or a hundred? Could you keep the roaches "out" long enough to feed that many T's?
Fruit flies would be great for slings, but again what about a couple hundred 2nd instar's? Even if you don't have to hunt and capture the flies or pin head crickets feeding 300 slings would require they feeders be out an hour or so.


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## Stylopidae (Dec 27, 2007)

matthias said:


> fascinating!
> 
> If you gave them more CO2 would they stay out longer? Any problems with repeated exposures?
> 
> ...



They take a bit longer coming to...and when they do come to, they're generally less active. What I refer to as the 'hangover effect'.

I just got done feeding about 30 slings right before work and because I didn't have to continually chase the feeders down, it took me about 5 minutes instead of 15.

I'm going home in a few hours to feed about 20 more.

My collection really only consists of about 100 individuals, so I don't know how effective this would be for larger collections. I stagger my feedings throughout the week, so it's rare for me to be feeding over 25 individuals at one time. I got the idea for alka-seltzer from Hedorah99, who uses a similar method on the fruit flies he feeds his collection.

They all came to about halfway through, but didn't move all that much. In fact, even the large roach in the video really only moved when I prodded it.

So they don't have to be completely out or unresponsive for this to still be effective.

I did all my tests on this with the same 3 roaches. The second time, it took about twice as long for them to become responsive again. The third time, it took a bit longer than the second. The more you knock them out, the longer they take to come to. I'd imagine there is a point where they won't come to any longer, but I didn't test for that.

Roaches tend to be pretty resillient, though and in biology classes I kept fruit flies knocked out for half the class and lost about a dozen when a hose got disconnected without my knowledge so that limit is probably pretty high.


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