It is very important NOT to give your pet Rat Hampster food, they need a completely different diet. Make sure fresh clean water is always avalable for your rat. A good Rat Pellet based foods such as Reggie Rat is a good base food for them which can be bought in most vets and pet shops, also fresh fruit and vegatables can offer your Rat alot of nutrients. Giving your Rat large amounts of fresh fruits and veg however can give you Rat a tummy upset, small amounts are recommended. Rats also need protien in their diets, this is already in most dry Rat foods, but a dog biscuit for a treat will go down well. Small amounts of cooked meat can also be given as a treat. Avoid giving Rats anything too fatty and sugary, and most left over foods. They might eat most things, but they can get tummy upsets quite easily from Human foods. My vet always advised me not to give Rats Peanuts, as they can be too rich for their digestion.