These are our first guinea pigs.

But about 4-5 years ago, we got our first hamster. A young male, maybe 2 months old, the store said. Gave him to us for free, said he was the last of a mom & babies that someone dumped on their doorstep, they found the container with mom and a whole load of babies on the step in front of the door when they came to open up one morning. He was separated, all alone, in a small tank in the back of the store. Since they didn't pay for him, they couldn't sell him, so they gave him to us for free. We did, of course, buy some supplies there.

Twelve days later, I notice He has suddenly gotten very large and fat. I search the internet. We keep trying to get a good look at his nethers through the side of the cage, because suddenly he doesn't want to be held and bites. Then I see it, both on internet and hamster. Only female hamsters have nipples. Oh no....

Sure enough two mornings later, "he" gave birth. Day 14 of our owning "him".

Gestation period is 14-16 days. I'll bet that store saw some "inappropriate" behavior and figured out they had "him" in the wrong group cage. And passed "him" off to us knowing full well "he" was likely pregnant. We haven't ever bought anything from them again, not even supplies, in protest.

But the kids were thrilled that instead of one young male hamster we ended up with four.

If the store made a mistake with these guinea pigs, we'd know by now, right? At six months old?