They can't get into the enclosures or anything, and I have the obt's kk weighted down. I just more worry that they will annoy the spiders. They are definitely awesome for escaped crickets. The other day I had bought about 10 pinheads for the babies, and I emptied the bag into a larger tupperware container to make it easier to catch them. Anyhow, I went ahead and fed the babies, and then started cleaning up the various items I had out (catch cups, paint brush etc), and I picked up the tupper ware container and tossed it into the empty 10 gallon tank I keep everything in....only to remember a few mins later that I had put the crickets in that tub. Little pinheads jumping around everywhere LOL. Brought in the cats and all was right with the world again.