After centuries of evolution as a creature of prey, your rabbit is the very model of defense: Nearly every sense has evolved in response to centuries of ancestors defending themselves from predators. For example, a rabbit's large ears aren't just for show; they do allow him to hear better; your ever-alert rabbit is a powerful sprinter and burrower as well.
A rabbit's eyes are on the sides of his head, providing him a wide range of vision; he can even see behind himself to allow him to spot predators and can move each eye independently from the other. One disadvantage to those abilities is that your rabbit has a small blind spot directly in front of his face; he has to tip his head and scan the forward area with one eye to see straight ahead.
Your rabbit's eyes are one of the best indicators of illness, so check them every day: They should be clear and bright.
A rabbit has a sharp sense of smell, and he often finds food underground simply by sniffing it out. No one is sure why he twitches his nose frequently; experts think it is part of his keen sense of smell and it also helps him gain other information about his surroundings. A rabbit is nearly odorless - this is an additional natural defense from predators.
Your rabbit's long ears are what allow him to hear so well. Hearing is his best sense. His ears can swivel in the direction of sound and make out even the faintest noises.
Mouth and Teeth
You'll notice your rabbit's split upper lip, which gives him more flexibility when eating. His front incisors are continually growing, and he keeps them short by chewing and gnawing. You should make sure his teeth don't get too long, because that can cause feeding problems.
A rabbit uses his whiskers like antennae to feel things, such as the walls of a tunnel. He also knows exactly what his own burrow feels like and knows immediately whether or not he is home.
Your rabbit has soft, glossy fur that is usually quite thick and helps him to adjust to changes in temperature. When he is four months old, and twice a year thereafter, he will lose all of his fur and quickly grow a new coat; that's just molting, and it's nothing to be concerned about. Molting begins at the front of the shoulders and works its way back.
A rabbit's strong hind legs help him run: Your rabbit is agile and a good short sprinter; a cottontail rabbit can run up to 35 miles an hour, although not for long. His large hind feet and leg strength also help protect him: He can kick predators in the teeth and make thumping noises with his feet to warn others; he uses his front legs to eat and burrow.
Although your rabbit is usually quiet, he can make vocal sounds, many of which humans cannot hear. He can growl, squeal, gnash his teeth, purr and make blood curdling screaming noises when in pain or caught by a predator.
A normal, healthy rabbit can be up to 18 inches long and can weigh up to 11 pounds depending on the breed.
Anus and Droppings
Your rabbit will urinate very little. His daily droppings should be round and hard and his anus clean and dry. Rabbit droppings are full of nutrients. Rabbits also produce something called a cecotrope. Cecotropes consist of essential nutrients that your rabbit needs to survive, which is why it looks as if your rabbit is eating his droppings; he's actually eating his cecotropes. Also, an added benefit for having a rabbit - if you're a gardener, rabbit manure makes excellent fertilizer.