do slow worms live in groups my son has one in a large fish tank saved from the cat and it has brought another one home but unsure if i can put them together.
Whenever I lift the piece of tin I have in my back garden, put there to encourage slow worms, there are always 6-7 of them, you shouldn't really keep them indoors though, I can understand that you don't want the cat to get them, they are a protected species, ring your local RSPCA and ask for their advice.
I went over a couple with my lawn mower by accident. I get them every year, loads of them, I think they nest in one place. They seem to work there way indoors occasionally.