I use a nice tall tub so there is no way they can get out. I know they can't climb smooth surfaces, but every once in a while one will make it halfway up a side. My tub is roughly 18"L x 12"W x 18"T. I started with a mixed colony of 200 and now I have at least 500 even though I feed them off almost every day. Keep them nice and warm and they will breed faster for you. I use a 11x11 Ultratherm heat pad from ReptileBasics http://www.reptilebasics.com/ultrath...th-11-x11.html on full power. The inside bottom of the warm side of the tub get up to 92-95 degrees with an ambient around 83-85.