Although your hamster mix, if a quality, specially prepared brand, will provide your hamster with a completely adequate basic diet, hamsters also enjoy fruit. However, it is important that fruit should be introduced to a hamster's diet gradually as a sudden large amount of fruit can cause tummy upsets and diarrhoea. Disturbing the gut flora of a hamster can be fatal, therefore to begin with the hamster should only be given a small piece of fruit once or twice a week and over a period of weeks this can be increased to a small piece every day. If at any time the hamster shows signs of diarrhoea all feeding of fruit should stop until the hamster has recovered and then gradually re-introduced into the diet.
Bear in mind if you are also feeding vegetables, to further reduce the portion size of fruits, and increase the time scale for introduction. I prefer to alternate fruits one week vegetables the next depending on availablity in my local supermarket. Fruit tends to spoil quicker and should be carefully monitored in the warm, summer months, and all excess removed before mould can develop. Over-ripe fruit can also attract unwanted bugs such as fruit flies to your hamster's enclosure. Do not allow your hamster to store fruit overnight in his/her bed.
Apple is a great treat and helps to soothe upset tummies. I give all my babies apple purree as their first introduction to fruit. I am not someone who eats their apple cores
and give mine instead to whichever hamster is lucky enough to be awake when I walk past their cage. Seeds can be removed if desired, though if you miss one don't panic.
Avocado (preferably skinned and seedless) - is it a fruit or a vegetable??? I give this to pregnant mothers, and don't worry if it has a bit of Marie Rose sauce on it, or even a prawn or two they will love it regardless.
Banana (skinned) - a lovely summer treat if you lightly freeze slices between layers of clingfilm. Tastes just like toffees if you fancy a try yourself. Goes off very quickly, so offer sparingly.
All berries are hugely appreciated by hamsters - Blackberries,
Blueberries, Blackcurrants, Cranberries (dried or fresh), Gooseberries, Loganberries, Raspberries, Redcurrants, Strawberries, and a local favourite Tayberries.
Cherries (stones should be removed as they can be dangerous if gnawed through) - not cocktail cherries please only fresh
Dates and Figs (dried or fresh), in fact most dried fruit goes down very well. My guys love apricots, prunes, sultanas, raisins, and cranberries. And if I am feeling very generous they may get some of my exotic dried fruit selection (see below for examples of exotic fruits safe for hamsters).
Grapes (black, red or white preferably seedless) - try frozen again in hot weather
Chestnuts (cooked)
Hamster love exotic fruit salads - Kiwi Fruit is quite acidic but I find babies love it, and is very high in vitamin C. Apricot, Clemantine, Greengage, Guava, Kumquat, Lychee (shelled), Mandarins, Mango, Nectarine, Passion Fruit, Paw Paw, Peach, Pear, Plums, Sharon fruit, Star fruit, and Ugli. All large internal stones should be removed as far as possible. Some hamsters are not keen on citrus fruits and I tend to avoid them personally. With so many other choices it isn't hard to find something else.
Melons of all varieties including Canteloupe and Watermelon. These can be skinned and deseeded if you want, and again try freezing in summer. Less is more with this fruit due to its high water content and speed to spoil. I find some hamsters wont touch the seeds, others love them.
Please don't feed them raw Rhubarb, only cooked, and no leaves. similiarly no tomato leaves (again is tomato a fruit or a vegtable? If a fruit, then it is okay to give them cooked or raw. There is nothing more amusing than watching a hamster chase a cherry tomato around his/her enclosure like football.) Conversely Raspberry leaves are actually good for them, especially if they have an upset tummy, as they can help firm up stools.
If you come across something missing please let me know, or a fruit you are unsure of please just ask.