Advertisement Mites are one of the big topics that turn up over and over again. I can't count how often I've posted about them and tried to put a rational view on some rather phobic reactions. So, here is a consolidated post with everything about mites that I (and others) can link back to: Mites are harmless – that needs to be said first. The mites showing up again and again in tarantula enclosures or, more often, in feeder colonies, are grain mites and related groups (genus Acarus) - scavenger mites that live off rotting organic matter. They feed off anything they can find, including spider poop, boli, and, if things get bad, even rotting coco fibers. As such they are actually beneficial – they help clean up the enclosures, the same way springtails do, but for some unexplained reasons springtails are loved whereas mites are considered the bad guys, very undeserved. Mites in small number are actually beneficial – no need to get rid of them. But what about those mites that attach themselves to your tarantula, often sitting at the base of the chelicerae? Those are parasites, right? – Wrong. When mites come upon bad times – little food, drought, overpopulation – they’ll want to emigrate. Unfortunately mites aren’t built for walking (longer distances) so they go looking for a convenient ‘bus’, something that can carry them far away. In that case your tarantula comes in handy. The mites, now called phoretic (‘hitchhiker’) mites, climb on board and find a place with softer skin to attach themselves with their mouth parts. Prime real estate is the area around the chelicerae because that area actually has food service: every time the tarantula eats the mites get to clean up afterwards, or even during feeding, and get dinner, too. They are kind of… ewww… but still harmless. They just sit there, they don’t suck hemolymph or anything else from the tarantula. Still those phoretic mites are really kind of… ewww. Want to get rid of them? Don’t try to brush or rip them off. That can actually damage the exoskeleton of your tarantula since the mites have attached themselves securely. Instead do something counter-intuitive. Place a small peace or rotting organic matter (fruit, veggy, or a dead cricket, whatever, the mites are not picky) in with your tarantula. The mites will smell the food and leave their ‘bus’ to have dinner. Take the rotting whatever out after a few hours, preferably using a spoon, so that all mites feeding on their feast will be collected, too. Rinse and repeat. The one problem about mites is that in favorable circumstances (moisture and plenty of food) they can explode in numbers. Within days they are everywhere, a moving avalanche of annoying little freeloaders looking for a good life. This situation actually happens very rarely in a tarantula enclosure since even a moist one usually does not contain enough food for a mite explosion but it does happen more often in feeder colonies. If it does happen in a tarantula enclosure it annoys not only you but even more the poor spider that cannot escape those millions of nuisances. The spider will stand on tiptoes, move a lot and scratch itself. Now what? Step one: wipe everything wipe-able off, but use only water. Chemicals are a bigger danger for your tarantula than for the mites. Wait a few hours for the next wave of mites to arrive, rinse and repeat. Step two: dry your tarantulas enclosure out and make sure to remove boli and anything rotting in there. If you have a mite explosion something has gone wrong in the first place. A well kept tarantula enclosure can and will support a mite population but its proliferation will be limited. Step three: get springtails. They will compete with mites for resources and keep them in check. So you want to prevent mites because you just don’t want phoretic mites on your T or a mite explosion in your enclosures? Bad news: you can’t. Mites are lightweight, small, and everywhere. They come in through the air. They will always come in through the air. Good news: they are harmless. I think I said that already. But what about sterilizing the substrate one way or other? That will kill any mites, right? Yes, it will, and it will kill anything else living in the substrate, too. The first thing to arrive on this wonderful, pristine substrate will have it all to itself – paradise. What do you want to bet that the first thing to arrive will be a mite? And if it isn’t a mite it’s a fungal spore. What do you like better? But what about those real tarantula parasitic mites? Those do exist (from the mite family Laelapidae), but they are rare and scientific literature about them is even rarer. They do need to come from somewhere, though. Real parasites are specific, tarantula mites don’t come in on a cricket or any other feeder, they only come in on another tarantula and a wild caught one at that. As of yet, nobody has managed to breed those rare and exotic mites in captivity. Is your tarantula wild caught? If not it doesn’t have a parasitic mite. And if it is wild caught? Parasitic mites don’t sit around the chelicerae usually but attach themselves at the edge of the carapace. If you really manage to find one – admire it and marvel. It’s much rarer than your tarantula. And unless the spider has a whole bunch of them it’s not going to do much harm either, they don’t suck that much hemolymph. I have no clue how to get them off since no one I know, have ever talked to, or ever read about has ever been in the situation. Personally, I’d document everything about the mite(s) and write a scientific paper about it , like these people did. For a mite researcher's take on this topic read this.