At what age can you feed hamsters vegetables and fruit?

you can feed fruits or vegetables to a hamster. but not all types of fruits and vegetables are suitable for hamsters. bananas, yogurt drops(from pet stores), carrots, Apples(not skin)and a little fresh squeezed orange in seeds or regular food is good but things like lettuce, grapes, celery or watermelon are too stringy. dont take chances with their diet. small seving sizes, stick to the size of your finger nail.