For most rabbits its natural to do so but some first time moms will not. You can just brush them and take that fur and put it into the nest box.
Yes when a female rabbit is pregnant it pulls out it fur to provide warmth for the baby rabbits
Female rabbits do not rip their fur. When they are preparing to have babies there bodies release a hormone that allows the fur to come out. In the wild, baby rabbits are born underground where it is cold and damp. They pull their fur to keep the babies warm.
I have found that with my own rabbits they started to pull their hair out when they are fertile in preparation for being pregnant. The rabbits I had did this when there was no other rabbits around, and the vet I go to said that when they start it is a sign that the bunny is becoming mature.
They will make their nests out of straw and fur.
The female rabbit pull out it fur in the last stages of giving birth
Generally very soon. If she is a first time mother, she may pull out her fur directly before or even after giving birth. The more seasoned the mother, the sooner she will tend to pull out her belly fur, but typically no more than two weeks before birthing. It's also common for female rabbits to have a "false pregnancy." She'll pull out her fur and make a nest, but she's not pregnant. This is one reason among many to spay your rabbits. See the link below for details.
Two male rabbits may well pull fur off each other. No matter the sex of the rabbits, this is aggressive behaviour: fighting. (Females tend to pull fur off themselves for their nests, not other rabbits.) You should separate the rabbits because fighting can lead to serious injuries, as well as emotional trauma. Only rabbits that are bonded should be allowed together. See the related questions below for more info.
Sometimes they have false pregnancy's.
she is pregnant
Sometimes rabbits have a 'dewlap' around their neck. Male rabbits can have one too but it is significantly larger when a female has one.
Rabbits usually pull their fur and make a nest the evening or day before giving birth. If they have made a nest & pulled fur but still no babies DON'T PANIC! Let mother nature take it's course and everything will come at the right time. ;) Answered By: a Rabbit Pro.
Female rabbits pull their fur and gather it into nests when they're pregnant or when they're going through a false pregnancy. False pregnancy is something female rabbits do because of their sex hormones, even when they haven't been near a male rabbit. False pregnancies are stressful for rabbits, and stress leads to a low quality of life and even illness, so it's a good idea to spay your rabbit so that it won't go through false pregnancies anymore. There are many good reasons to spay/neuter rabbits. See the related link below for info. There are other reasons rabbits might pull their fur out - like stress, extreme boredom, illness, parasites - but if the rabbit is gathering its fur then generally the reason is pregnancy or false pregnancy.