Sharing my current treat list, because I spent the first few months buying colourful things from the pet shop that were mostly sugar.

The photo is a dried shrimp, which is still his favourite and the one thing he will climb into a basket for.

What works for us:

- Dried shrimp and dried mealworms. Small, high value, easy to break in half. Two or three pieces is a treat, a handful is a stomach ache.
- A piece of walnut or a single sunflower seed. This is the "I need you to come out of the burrow right now" button. Use it sparingly or it stops working.
- Fresh veg in tiny amounts: broccoli stem, cucumber, a bit of carrot, sweet potato. Thumbnail sized. What I did not know at first is that fresh food spoils fast in a warm cage, so it comes out after a few hours whether it is eaten or not.
- Herbs: dried dandelion, parsley, chamomile. Cheap, they last forever, and they are good scattered through the bedding so foraging is a thing he can actually do.

And the things I stopped buying:

- Yogurt drops and honey sticks. Basically sugar. They were the reason one of my hamsters got picky about actual food.
- Anything with a long ingredient list. If I cannot pronounce half of it, it is not going in the bowl.
- Nut and seed mixes with dried fruit, which is mostly sugar and sticks to their pouches.

Two habits that helped more than any specific treat:

1. Treats come from my hand, not from the bowl. That is what makes taming work. It took about three weeks of doing this every evening before he stopped flinching.
2. Weigh the food, not the treat. I give roughly a tablespoon of pellets a day plus a small scatter of seeds, and I use the kitchen scale once a week. Sudden weight loss is the earliest sign something is wrong, and you only notice it if you have been weighing all along.

One caution: if you are not sure a food is safe, do not "try a little and see". A few common fruits and anything from the onion family are genuinely not safe for them.