Yes, and that's actually better because inbreeding can cause genetic disorders.
If the buck is the father there is hardly any chance since they are not lust seekers.They mate to pass their genes. I kept pet lab rats for years and the parents ate the babies from their own litters on a regular basis. This action ,if done by the father ,will prompt the female into estrus(heat) again.
In a female rat's lifetime, they can have around 5 litters, each litter having atmost about 14 babies. So that's like around 70 babies per rat's life!
Rats mate all year around. They might even have 100 babies in their lifetime!
To mate most likely.
== == They can have anything between 7 - 20. Our school rat had 16.
They atleast have 1 per mate with the father but they mate their own siblings
Yes. Rats are social animals and do well in groups. They do fight at times and if there is a bully in the cage, that rat should be removed from the group. In many cases, the bully will be a male rat.Female rats from different litters are likely to get along well. You shouldn't have any problems. Do offer enough hide-aways and beds that they can get away from other rats if they so desire. In most cases, the rats will want to be together but they should have options.
they mate like any other mammal
No. It is not legal nor physically possible.
I don't believe they can, because if rats from the same family mate, it can cause problem with the young babies, chances are they might not survive or have severe problems
They should have at least one other cage mate so they do not get lonely and stressed out.
Rats are a type of mammal, and as such, they reproduce in essentially the same way that other mammals do. Baby rats gestate in their mother's uterus and when they are ready, they come out. The major difference between the birth of rats and the birth of human beings is that rats always have multiple births. They are born in litters. Humans are usually born one at a time.