Found a freeloader spider in my spider's enclosure... HOW???

[spoper]

I have a juvenile Pardosa Hortensis that I keep on my table next to my computer. I look at it quite frequently every day, I watch it hunt and eat and do its spider-things.
Today I sit down and see a slightly bigger, white-yellowish spider with transparent legs and I thought it molted! That's crazy I thought, and started taking pictures... until I noticed movement in the background. It was my Pardosa Hortensis running around in the back!! What!! There is another spider in the enclosure!! HOW?! How can this happen?

I feed the spider meal moths and never leave the enclosure open - the enclosure even has a feeding hatch, so I almost never really open it. There are no holes anywhere on the enclosure big enough for this freeloader spider to have made it in here. It is slightly bigger than my Pardosa. I'm so so confused!! Anyone have any ideas?

I did get some dirt from outside when I made this enclosure, but that was over a month ago, and I never once saw this spider ever in the enclosure, and as I said I look at the enclosure every single day, several, easily dozens of times!

 

[ArynAlba]

Hmm, what kind of wood are you using? If it's cork (or I guess if it's just wood/bark with a bunch of small spaces in it), it could be possible that this little fellow was hiding in one of the nooks and crannies as a sling, and you didn't see it until now?

Would you be able to get a better picture of the freeloader so we can take a crack at ID'ing it? And maybe give an approximate location (it's possible it's not native to your area, but just in case it is, I guess?)

 

[spoper]

Here's a better picture for ID, I'm trying to find out what kind of spider this is - based on pics I found I'm guessing a type of yellow sac spider?

 

[spoper]

Hmm, what kind of wood are you using? If it's cork (or I guess if it's just wood/bark with a bunch of small spaces in it), it could be possible that this little fellow was hiding in one of the nooks and crannies as a sling, and you didn't see it until now?

Would you be able to get a better picture of the freeloader so we can take a crack at ID'ing it? And maybe give an approximate location (it's possible it's not native to your area, but just in case it is, I guess?)

The wood is from a willow that was torn out by a strong wind 2 or so months ago - I took the pieces of wood from its insides right after the storm, and they were on a windowsill inside my corridor for a good couple of weeks. Then when I found the Pardosa Hortensis and decided to keep it, I put them inside the enclosure. This was over a month ago, never seen this spider until now, so so confused and bewildered!

 

[spoper]

I will also add, the pieces of wood have no cracks or anything in them, and I personally broke them off from the tree, so I wouldnt say it's likely it was hiding in there. But how else? I used dirt from outside, and mixed it with this "dirt for spider enclosures" I bought from an exotic pet shop, but again, I put all this stuff in the enclosure over a month ago, and it was hot then and now, so I dont think the spider was in hybernation until now, burrowed?

 

[ArynAlba]

Here's a better picture for ID, I'm trying to find out what kind of spider this is - based on pics I found I'm guessing a type of yellow sac spider?

I'm definitely not an expert, so please take this with a grain of salt! But the eye patterning and overall appearance do indicate some sort of sac spider to me as well. If so, these guys can tend to wander in order to hunt and find food--could it have gotten in through some ventilation holes, and then molted so that it was too large to escape out of said ventilation?

 

[spoper]

I'm definitely not an expert, so please take this with a grain of salt! But the eye patterning and overall appearance do indicate some sort of sac spider to me as well. If so, these guys can tend to wander in order to hunt and find food--could it have gotten in through some ventilation holes, and then molted so that it was too large to escape out of said ventilation?

Unless it mulitplied its size many times, I don't think so. Here's how big the enclosure's vent holes are

 

[Tbone192]

Only other thing I could think, less likely, but could it have hatched in the enclosure. Then eaten all its best mates until it got big enough to bully your poor spider out of its meals. Either that or it was hiding in a branch as a sling and grew up as mentioned above. Sometimes when dealing with my male noble false widow (Steatoda nobilis) I often lose them in the enclosure because they are so small and stealthy.

 

[ArynAlba]

Unless it mulitplied its size many times, I don't think so. Here's how big the enclosure's vent holes are

Actually, that doesn't look like too big of a stretch, haha (as long as I'm seeing your photo right).
Spiders can typically get through holes that are about as large as their carapace--and it looks to me like the ventilation holes could've been a bit wider than this spider's carapace within a molt or so. The legs can be a little deceiving--spiders can bend them quite a bit in order to wiggle through smaller spaces than you'd think!

 

[spoper]

The reason I'm doubtful it lived in the enclosure all this time is because not only did I never see it, my Pardosa didn't kill it (or vice versa), and I'm doubtful it could get food because I almost always saw my Pardosa with its prey - but then again, I know they can survive quite a long time without food.

 

[jbooth]

Yellow snack spider... my wolf spiders love them, but bigger wolfs, they can get into anything and walk on glass, may pose a threat to a smaller wolf spider. Not sure how the one in my roach bin got there either, but it's fatter than I've ever seen one.

 

[spoper]

Yeah I was immediately worried for my lil wolf spider's safety and removed the intruder! If my wolf spider was bigger I'd let it eat it haha

 

[spoper]

Also this intruder spider is very pale, which makes it easy to see it against the soil of the enclosure. As I was removing it, I never had to search for it, but my Pardosa blends in so well, it's like playing Where's Waldo every time I look for it and it's not on top of the wood pieces! Since I scan the whole enclosure several times a day meticulously to spot it, I dont think it'd be possible for me to miss this other spider for any more than a day. I'm still absolutely bewildered at this!

 

[Ultum4Spiderz]

The wood is from a willow that was torn out by a strong wind 2 or so months ago - I took the pieces of wood from its insides right after the storm, and they were on a windowsill inside my corridor for a good couple of weeks. Then when I found the Pardosa Hortensis and decided to keep it, I put them inside the enclosure. This was over a month ago, never seen this spider until now, so so confused and bewildered!

A housepider easily could had nested inside your wood while it was sitting on the window sill.

 

[spoper]

A housepider easily could had nested inside your wood while it was sitting on the window sill.

The wood has no cracks or holes on it I think it's unlikely that it was hiding inside it

 

[Ultum4Spiderz]

The wood has no cracks or holes on it I think it's unlikely that it was hiding inside it

Then there’s no explanation to how this Houdini spider made it in your spiders enclosure. 🪄🪄🪄🪄

 

[darkness975]

It squeezed through the mesh ventilation holes.

 

[The Snark]

Two aspects humans constantly think. Time frame and physical-physiological properties, according to human standards. An araneus parked in a window in a skeletal web in November and became an immobile fixture decoration until May. That stray spider looks recently molted. The exoskeleton plastic and mold-able, certainly able to squeeze through impossibly small spaces.

 

[darkness975]

Two aspects humans constantly think. Time frame and physical-physiological properties, according to human standards. An araneus parked in a window in a skeletal web in November and became an immobile fixture decoration until May. That stray spider looks recently molted. The exoskeleton plastic and mold-able, certainly able to squeeze through impossibly small spaces.

They usually die at the end of the season when adults but if they're younger they overwinter.

 

[jbooth]

Got in when it could, can't get out now