Thanks! I have 9 Exo Terra terrariums of various sizes and the rest of my mantises are either in deli cups or converted food containers. The terrariums are planted but for deli cups I use sphagnum moss for the substrate. I started out using coconut substrate and liked it's softness & ability to hold water but unfortunately it grows mold really quickly where I am (sometimes in as little as 12 hours, the mold spore count is always really high here.) I tried using paper towels for a while, they make cleanup easy but they dry out way too fast. I finally switched to sphagnum moss and it works a lot better. At first I tried ground up sphagnum moss like for mixing into potting soil but I didn't like the consistency, it was too fluffy and didn't soak up water very well so I got whole dried sphagnum moss and cut it into smaller pieces with scissors. Not sure why but it seems to hold water better and doesn't have that weird fluffy texture. And it doesn't grow mold like coconut fiber. Sphagnum moss comes in brown or green, I buy the green kind it looks really nice in deli cups. For the mantids that require lower humidity I use reptile carpet in their deli cups. Its meant to line reptile aquariums, I just bought a large sheet of it and cut out a bunch of circles that fit in the bottom of the deli cups. It's easy to clean, looks nicer than paper towels and will absorb a little bit of water if needed.
