To be safe, don't feed your rabbit anything that isn't recommended for rabbits. See the related question below for more details about a healthy rabbit diet.
If you want to feed your rabbit a new plant, always check unknown plants against a list of poisonous plants for rabbits (there are a few on the web -- one is linked below). Do research online to see if the plant is recommended for rabbits. If you decide to give it to your bunny, start off with tiny amounts, and watch the rabbit's health for bad reactions (diarrhea, gas, pain, etc).
Rabbits cannot eat the following:
About treats: Rabbits can have many fruits and vegetables as a treat -- like cucumber, carrot, tomato, apple -- but too much of these foods will make them sick. The House Rabbit Society recommends no more than 2 tablespoons of fresh treat food per day for a normal, healthy 6 pound rabbit.
About lettuce: Lettuce has natural compounds that can give rabbits diarrhea and make them seriously ill. Light-coloured and white lettuces contain these compounds most (like iceberg lettuce); also, light-coloured plants don't have nutritional value for rabbits, so they should be avoided. Dark-coloured lettuces (like the dark adult leaves of Romaine, Green Leaf, Red Leaf) are good for rabbits in moderation: they can be included in the rotation of "salad" greens but shouldn't be offered every day. Rabbits in the wild can eat lettuce because they are also free to eat herbs and minerals that counteract the lettuce's effects; you can mimic this diet with a rotation of herbs, weeds, and other greens in your rabbit's salad. Dark lettuces are less likely to give the rabbits diarrhea but some people say why risk it when there are so many things you can feed them?
More Information about What Rabbits Can and Can't Eat
Bunnies love, radicchio, endive, dutch carrot tops (occasionally), silver beet, spinach (occasionally), basil, parsley, collard greens, mint, mustard greens, , cilantro, mint, strawberry leaves, raspberry leaves, wheat grass, and dandelion leaves and flowers.
They need a good mixture of those veggies fed in relation to their weight. About 1.5 cups of vegetables per kilogram of body weight each day. Only a small amount of pellets, about three tablespoons. Ignore anyone who says rabbits need tonnes of pellets : my vet says no to pellets. They will make your rabbit fat and sick if you give too much. And they need unlimited timothy or oaten hay.
Also grass gives them gas, and rabbits can't fart or burp, so too much grass is a bad thing. Domestic rabbits are nothing like wild rabbits, as they've evolved differently. And rabbits do need to be protected from poisonous things as they do not know whether something is poisonous or not. They test their environment with their teeth. And of course, always have lots of clean fresh water for your bunny. And no iceberg lettuce! It gives them diarrhea.
As treats small amounts of fruits like strawberries, apples (but not the seeds, which are poisonous), Pears, cherries, blueberries, grapes and bananas. Definitely not too much, because sugar is bad for rabbits and can make them really sick. Fruit and pellets are junk food for bunnies!
Acid fruits, like tomato, orange, mandarin, and pinapple. They love apples and of course carrots. You can give them pretty much all vegetables.
[edit] Rabbits actually can eat pineapples and Oranges. The acidity will clears up any hairballs they may get, considering rabbits cannot throw up. However, they should only eat it in small amounts
Some things rabbits can't eat (this is NOT a complete list! To keep your rabbit safe and healthy, think not about what they can't eat, but what they CAN eat. See the related question, linked below, for more information):
Amaranth
Arrowgrass
Bracken fern
Bromweed
Buckeye
Burdock
Castor beans
Cherry leaves
Chinaberry
Chokecherry leaves or pits
Comfrey - Personal note: some folks feed this with no problems.
Fireweed
Foxglove
Goldenrod
Hemlock, poison/water
Horehound
Jimson weed
Johnson grass
Larkspur
Laurel
Lupine
Mesquite
Milkweed - personal note: yet wild bunnies have been known to eat this no probs.
Miner's lettuce
Moldy bread, moldy anything
Oak
Oleander
Pigweed - personal note: mine will eat the young leaves, they leave the stalk and older leaves
Poppy
Potato leaves, sprouts, or peels
Rhubarb leaves
Soybeans or soybean vines
Sweet clover - personal note - what's wrong with clover?
Tarweed
Tomato leaves
Also, don't give rabbits vegetables straight from the fridge. The coldness will upset the rabbits' stomach and it will have a diarrhea. And believe me, it's not fun cleaning diarrhea up.
Don't feed your rabbits a lot of salad greens. This may seem funny to you because rabbits eat greens but that is not all rabbits eat in the wild. They can eat roots and berries and get a varied diet. If all you feed them is greens they will get diarrhea. Feed your rabbit a well rounded ration of rabbit pellets.
Floppy-eared rabbits (they're called "lop" rabbits) have the same basic behaviours as all other pet rabbits. They do the exact same things all day as other pet rabbits. See the related question below for the answer to this question.
The only behaviour difference between floppy-eared and normal is, because rabbits communicate with their ears (different positions and angles mean different things), floppy-eared rabbits might have a slightly different communication style.
Lop-eared rabbits (this is what floppy-eared rabbits are called) have the same diet as all other pet rabbits. The ears don't affect what the rabbit can and can't eat.
There are a lot of things rabbits can't eat. It's easier to say what they can eat, because everything else is something they can't eat.
Rabbits CAN eat hay, high-quality pellets, and certain fresh vegetables and fruit.
The HAY should be grass hay (like timothy, brome), if the rabbit is a normal healthy adult. Legume hay (like alfalfa, clover) is good for babies, pregnant/nursing rabbits, and (in some cases, under direction of a vet) elderly or sick rabbits.
The VEG & FRUIT should be limited. Too much will make your bunny sick. Dark leafy greens are the best; all others should be considered treats. Some plants are dangerous, even poisonous, for rabbits, so do some research before giving any plant, vegetable, or fruit to your rabbit. See related questions and the link below.
What Rabbits Can't Eat
Do NOT give your rabbit any foods made for humans, like bread, cereal, oatmeal, crackers, cookies, cake, candy, chocolate, pasta, sauce, and any veggies/fruit that have been processed - nothing canned, cooked, frozen, dried, jarred, etc.
Do NOT give your bunny nuts or seeds.
Do NOT give your bunny food made for another pet, like dogs, cats, guinea pigs, etc.
Rabbits shouldn't eat poisonous plant such as eucalyptus deadly night shade and so on. They shouldn't eat lettuce either but they can eat dandelion leaves and celery and of course carrots.
Well rabbits hate to eat is durian fruit.. Because it is smelly for rabbits, but maybe other rabbits from different communitiy like durian but rabbits cant eat fruit so yeah!!!
Floppy eared rabbits eat the same as any other rabbit would. Fresh hay (replaced once a week), grass once a day, a pellet mix and fresh water (replaced once a day).
No, they do not. Rabbits only eat carrots and other plants. They are herbivores.
Yes. Here in Montana it is very common to see a weasel chasing a rabbit. They will eat them. Weasels are vicious and just as fast as rabbits.
Yes they do eat small rabbits, depending on the size of the owl. They also eat mice, rats, small birds, moles, shrews and other small rodents.
Yes, but rabbits eat carrots. I love rabbits, hug rabbits, and kiss rabbits. Rabbits love me! BTW, I attract girls blah blah blah?!?!
Rabbits prefer leafy greens and vegetables. If there is leftover salad, rabbits will consume that, they do not generally do well on cooked food and do not eat meat.
yes!foxes do eat rabbits
Man (carnivores) may eat rabbits, but rabbits (herbivores) eat plant life.
The impala is herbivorous; it does not eat rabbits.
rabbits don't eat animals they are vegetarian's.
rabbits can not eat lemons.Lemons are to sour for rabbits.
it is rabbits
Rabbits are herbivores and do not eat other rabbits! They only eat plant material, fruit, pellets, and vegetables.
No rabbits eat their feces, although all rabbits eat cecotropes. Rabbits have two kinds of droppings: feces, and cecotropes. Baby rabbits that aren't weaned yet eat their mother's cecotropes; once they're weaned, they eat their own cecotropes.
Full-grown rabbits are rather large for most snakes, but many snakes will prey on baby rabbits, and some of the larger snakes can eat adult rabbits.
Do rabbits eat paper?
Pigeons do not eat rabbits because they are too small.
rabbits and humans eat carrots.