Why should you not separate mating dogs?
Because when a dog mates with another they become bonded and love each other, therefore make better puppies the next time around.
Do you mean baby mice? Baby female/male mice can start mating at about 6 weeks, and you are safe to separate them from there mother at 4 weeks, so the ideal time to separate them is about 5 weeks. If you mean 'when should you separate adult mice female/male' You should always have them separate unless you want them to mate.
This part of the mating process is called the tie. The tie happens when the male's penis swells after ejaculation and the female's vagina squeezes to ensure that the semen gets and stays inside her. Usually what happens after mating is the male will twist around so that the two animals are facing in opposite directions. They will be 'tied' together. They may whine as if they are in distress however this is normal in…
A responsible owner will have its dogs neutered. If an owner prefers not to do this, the ONLY way to prevent mating is to isolate the female when she is in heat and not allow her to be anywhere near male dogs. Warning: a female in heat will do whatever she can to get loose because the breeding instinct is very strong.