My 3 year old recently took out our hermit crabs to "play". She then lost two of them. I found one and but could not find the other. I had read that they would go to shells. I placed the extra shells I purchased on the floor, and placed the aquarium on the floor. thinking he would miss his friends. Rascal was missing for one week. This morning I found him next to the aquarium, alive and well. Just wanted to pass on the hint in case it works for some one else- and I am excited to get Rascal back.