Odd Question

There seems to be little proof on the net of female rats retaining sperm, lots of hear-say and several articles claim it's not possible for a female rodent to retain for more than a few days.
I've produced hundreds of litters and I normally pull my females before dropping babies and I've never had a female retain or drop a 2nd litter unexpectedly.
Without scientific proof I'm still a skeptic but I wouldn't rule it out either.

Ill let you guys know how it turns out, I pulled her before she dropped so Im sure she has nit been in contact with a male since then.

iv actually got a mouse that is pregnant again, hasnt been with a male since ~2 weeks before the litter she has now. and hers are ~2 weeks old, so in another 2 weeks or so ill post another update.

but with the rat, yes she gave birth ~21-30 days after a litter (dont remember 100%, it was a while ago), and she was not in with a male from at least 1 week before that littler. so it does happen, period.

Well I went into the rat house this morning to check on the rat in question and she was sitting on a litter of about 12 pups....I guess it happens becaue I pulled her from the breeder tub while she was still prego....now unless one of her you matured really early and bred her then she had to retain sperm.

im quite sure it happens, because theres no question with mine, the previous litter hasnt even opened their eyes yet, so they def arent sexually mature

Well it's odd she had a litter but I must say the science of rats implies that sperm left over or remaining is destroyed in the vagina and cannot survive for very long outside of the body.