Chocolate is not poisonous to rats, as they are able to digest the chemical theobromine, which can be harmful to other animals. However, only use chocolate as an occasional treats, as although they do enjoy it, it can lead to weight gain and conditions such as diabetes. 


We are used to thinking of chocolate as a tasty treat. However, it is pretty well known that many animals such as dogs cannot consume chocolate as it is toxic to them and can cause digestive problems and can even lead to death. But what about a pet rat? Can they safely have chocolate as an enjoyable treat? And can we use this as a natural exterminator?

Can chocolate harm rats?


Rats can, in fact, consume chocolate safely. This is because they have the same ability to process the chemical ‘Theobromine‘ as humans. This chemical is what makes chocolate fatal to dogs and cats, as well as other animals. When they try to digest it, they cannot break it down properly, so it is toxic to them and can be very harmful.

However, there is still a lethal dose of theobromine for rats, although they are able to survive a much larger dose than other pets. On average, a rat would need to consume a large bar of chocolate, weighing 150g, to reach toxicity levels close to lethal. This depends on the size of the rat. Larger rats are able to take a higher dose without becoming ill. There is also variations in theobromine levels of different types of chocolate. Generally, dark chocolate contains a higher dose.

Symptoms of theobromine poisoning include vomiting, diarrhoea, and increased urination. More extreme effects of a toxic dose include heart attacks, seizures, internal bleeding, and death.

Even if you feed your rat a much smaller dose than this, the other ingredients in chocolate can cause more long term problems. For example, obesity, cardiovascular (heart and blood vessels), and respiratory problems can develop. Chocolate in general is very calorie-rich, and contains lots of fat, which can cause mobility problems in your rat.

What to do if your rat has eaten chocolate?


As discussed above, small amounts of chocolate given occasionally is unlikely to produce any ill-effects in your rat. If you think your rat has eaten a large amount of chocolate in a short time, contact your vet. Even if your rat has eaten a fairly small dose, if they are exhibiting any of the theobromine poisoning symptoms above, a vet should certainly be contacted.

Do rats like chocolate?


So if rats can safely eat small amount of chocolate, is it a good treat for them? Rats actually do enjoy eating chocolate, since they like the sweet taste just like humans do. This is because rats are omnivores like humans, and enjoy eating a wide variety of foods. Other animals, such as cats, are carnivores and cannot even taste the sweet flavour, so are unlikely to enjoy it. Rats in general have a preference for junk food, even if it is more unhealthy for them.

This makes chocolate great to encourage rats to consume prescribed medicine, by concealing it within the tasty treat.


Animal-Club provides animal parties or animal handling workshop where your will be able to see, learn and interact with the hamsters and other wonderful animals with the help of our presenters. Our mobile zoo has many friendly animals such as rabbits, tarantulas, geckos, vinegaroons and more that will be perfect for an animal party. We can also come over to your school for an animal school visit or arrange for an animal workshop with us where the children can learn about animals and have fun too.