Functional and Practical

I came up with this for our hermit crab tanks. Hermit crabs dig into the substrate to molt as they grow. The HC community calls that going away to camp. Sometimes they dig near the glass and form windows. Since it should remain dark these are perfect to place over the window. Instead of taping a piece of cardboard over the window, why not a fun reusable sticker! Thank you Sticker Mule!