Dry food for your chipmunk
I've made a distinction on this site between dry foods (seeds, nuts) and fresh foods (grapes, apples, avocados). Chipmunks are a little like people, in that they will have their favourite foods, and if you have more than one, each chipmunk could like different things. So when you first get your chipmunk you will probably be trying almost everything to find out what he or she likes. Chipmunks like and sometimes need to store food, but they only store dry food. It's very unlikely you will ever see your chipmunk taking something back to its nest that will rot.
When I got my first chipmunk I was warned not to give her too many peanuts, try to limit her to one a day they said. For chipmunks food like sunflower seeds and peanuts are high in fat. It can even be dangerous to give your chipmunk loads of worms for example. I must be clear here though, giving your chipmunk too much of the same thing will make them ill, so be sparing with foods you know are high in fat, and give them plenty of variety in their diets.
Yep, there really is a special food for chipmunks, muesli, but don't soak this muesli in milk. You will come across two types of chipmunk muesli in the shops. The one on the left is from Pets at Home, who have shops spread across the UK, the other is Burgess Supa Chipmunk mix. Both products contain everything a chipmunk needs to stay healthy, apart from water. But chipmunks like a varied diet so you will want to include some fresh fruit, and some supplements.
The muesli comes in 1kg packets, and an adult chipmunk will need around 30g of food a day. I put mine out in a dog food size bowl about 20cm across. The bowl needs to be heavy as the chippies like to perch on the rim, so they would tip up a lighter bowl. They tend to take the things they like first. It's all good for them, but I bet you find they will leave the little brown dog food type things until last.
Making your own muesli
There may be times when you run out of the commercial muesli, or you want to try to mix your own blend. I've run out sometimes and as a standby got a bag of Guinea Pig food from the supermarket and topped it up with shelled walnuts & almonds, a few sunflower seeds, dried raisins, oats and pine nuts. You could also see if your garden center has some squirrel feed which can be used as a standby.
I think peanuts are probably their favorite nuts, in their shells. Don't get any salted nuts or roasted ones either.
Given time, an adult chipmunk can probably get in to most nuts, but when their young you might want to help them out by cracking open the larger tougher nuts. Breaking in to nuts is great for a chipmunks teeth, which are constantly growing. Mine also like shelled almonds and pine nuts.
Seeds and grain
I've mentioned some seeds already, like mixed canary seed, sunflower seeds. Mine also like the seeds from butternut squashes, and the inside of pumpkins. Sprigs of millet intended for birds are also worth getting, they can sit for hours striping the seeds out of these. I found packets of hemp seeds in a small pet shop in Somerset, so I brought a couple of packets back for my chipmunks to try, they loved them.
If your chipmunks are out and about when you are eating they will not be shy in checking out your food, and nicking anything they fancy off your plate given the chance. That's how I found out they like oats sometimes, and toast even. Avoid giving your pet anything with refined sugar in, it's really bad for them.
These are a must have, here's a couple of photos of the type of supplement you need to have somewhere in their home. Of the two blocks, the Vita Mineral block has proved the popular one. When I first bought a block I thought I wasted my money, it will just sit there ignored for weeks, then one day you will find your chipmunk attacking it like crazy. I guess they know best when they need their minerals.