Rabbits cannot get pregnant without a male.
However female rabbits can sometimes experience false pregnancy called pseudopregnancy.
Female rabbits are fertile for most of the month, but they only produce an egg for insemination when mated with a male rabbit.
A female rabbit can also become pregnant again within a few days or so of giving birth.
A neutered male rabbit will sometimes still try to mate.
However once neutered the male rabbit will not try to mate as much although they will still often exhibit their mounting behavior as a result of hormonal influences or even from just behavioral patterns that are ingrained in them.
Once neutered though the male rabbit will not be able to get the female rabbit pregnant as the neutered rabbit no longer produces sperm.
Male and female rabbits fight for a variety of reasons which include establishing their dominance within their relationship and even for competing for food and other resources if the resources are scarce.
Male and female rabbits may also fight due to mating related aggression, especially when the female rabbit is not receptive or due to hormonal changes as a result of sexual maturity, stress from environmental changes or improper introductions when they're not properly bonded.
It's crucial to neuter rabbits to minimize any fighting by reducing hormonal influences on the rabbits behavior.
Rabbits are not rodents as rabbits are mammals that are in the order of Lagomorpha.
Lagomorpha also includes pikas and hares.
On the other hand rodents are in a separate order called Rodentia which includes marmots, squirrels, rats and mice.
Rabbits also have 2 sets of upper incisors and rodents only have one set of incisors.
A rabbits incisors are also larger and more prominent than rodents incisors and has a smaller set of peg like teeth behind them.
Rabbits are also herbivores which eat grasses, leaves and other plant matter and their digestive system is adapted to high fiber diets.
Although until the early 20th century, rabbits and lagomorphs were classified as rodents but rabbits are not rodents at all.