We got up to 33 at one point, which is fun because the licence plate on my car includes 33 GP. At that point, there wasn't enough lawn, especially in summer so we had to separate the boys and girls to stop the breeding. That was maybe five years ago. We're back down to five now, so some of them are around 7 years old, very good for a guinea pig.

I'd say 5 do around 50-100 sq metres.