- Litters are very preventable. There is (in my opinion) no excuse for an 'accidental' litter. Male rats (bucks) are extremely obvious! Does are obviously does too - only does have nipples and they are very easy to see. It's fairly straight forward to make a cage escape-proof. I've never had any escapes of any kind and I have kept entire bucks and does at the same time before (in entirely separate cages, of course.)
You sold the babies to a petstore?!
How do you know they weren't housed in a hamster cage on woodshavings or ended up neglected and unloved? The only litter I've ever had the pleasure of raising was a foster mum with her babies - the babies were one day old when they came here. There were 14 babies. I rehomed them all privately and checked out the people that rehomed them from me. Even then I have kept track of them throughout their lives and one of them has come back to me for her 'retirement' as her cage-mates had died and the owner did not want to get any more rats.
I find your post very upsetting and I just wanted to reply to it so that people reading this don't think this is a responsible way to keep rats because it isn't . Nor is this a 'typical' case of rat-keeping.
Oh and the red 'blood' you describe isn't blood at all. It's porphyin.
All the same principles apply to rats as they do to guinea pigs. Irresponsible breeding isn't excusable.