Chocolate should never be given to hamsters!
Author: Nadia VellaSource: www.hamster-club.com
Chocolate is very toxic to hamsters and should never be given, not even in small quantities.
Affected hamsters should be taken to a vet immediately since the hamster will need fluids, vitamins and warmth to help detoxify the body.
The above applies for human chocolate while pet chocolate is safe for animals.
But a small note: this type of chocolate may be sticky and may cause hamster cheek pouch impaction, so I do not advice in giving hamsters any type of chocolate.
If your hamster ate chocolate, you may use a homeopathic treatment which may help it feel better. The homeopathic treatment is Nux vomica - this can help the hamster feel much better. Nux vomica may be bought from an animal pharmacy or else from a vet.