They don't last too many years...I think 5-8? My daughter got a guinea pig when she was in college even though I told her not to. Then she said it was lonely so she got another and it turned out to be a different sex even though the pet shop said it was not. So they had babies. Then she didn't separate them in time so they had babies again. She was up to 7 guinea pigs at one point! And she was a college student who didn't work so I was paying for those things until she could find homes for them.