Hey love the knitted hammock of sorts! It looks like it's a cut out part of an old sweater or some such? If you want, I can give you directions on how to keep the edges from fraying and unraveling. Remember a crabitat is a high-humidity environment- that thing's going to stink like a used towel with mildew eventually. To prevent that, you probably want to clean it about once a week. You can do the same thing people sometimes do with sponges: put it in a dish with water, and stick it into the microwave for a couple of minutes so it boils. Since this is cloth, you'll then want to dry it out. First, spread it flat on a towel, and put another towel flat on top. Press down to get the majority of the wetness out. Don't wring the knitted fabric because it'll weaken it. Then hang both towels and the knitted fabric to dry the rest of the way, on a towel rod, a clothes line, or really anywhere else that dry air can get all the way around it.
They'll love moss
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My two crawl around and under the moss all the time. I hope to one day have a house with a bed of moss for part of the yard. It's so comfy to lie on, even for us
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I can see what the crabs like about it.