Keeping an ant farm can be a lot of fun and a good source of education if you have kids. The best part is that ant farms are basically independent. Your only job is to make sure the ants have enough food and water to stay healthy and strong.
Try Something Sugary
A mix of equal parts honey and water works well and you can serve it just a few drops at a time. The ants will find it and pick it up to eat it or store for later. You also dip a cotton ball into a mixture of water and sugar and drop it into the ant habitat. This will provide both water and food for the ants.
Tiny pieces of fruit such as apples or bananas also works, but keep the portions very small to prevent them from going bad and becoming odiferous.
Always start with small pieces of food and keep an eye on how much is consumed and how fast. Don't add more food until you see the previous one disappearing.
Provide Some Meat
Some ants are carnivorous and will appreciate sources of protein such as tiny pieces of dead insects. The easiest option is crickets, which can be bought frozen from pet stores and broken into small pieces.
Ants who enjoy meat products also will appreciate dog or cat dry food and even a bit of canned fish.
One thing to keep in mind: Food preferences might vary throughout the year. For example, ants might go for sugary foods during some months but focus more on protein at other times. So if your ants don't seem too excited about a cricket now, feed them something else and try again a few weeks later.
Water is essential to keeping your ants alive. Depending on the setup of your ant farm, you can provide water by making sure the dirt is damp or adding water tubes -- sold at hobby and pet stores -- to the box where your ants live.