Ants appear to be pretty harmless to most people. In the majority of temperate climates, ants do very little damage, although red ants bite people all over the planet. However, there are more serious ants in warmer countries and some of these ants can even be responsible for hospitalzations and even a few fatalities. Red ant bites itch or even hurt, but imagine a baby falling onto a red ant nest.
What if that baby fell onto a fire ant nest or a red carpenter ant nest? Carpenter ants can be an inch (25 mm) long and a bite can draw blood. There are poisonous ants in South America and exploding ants in Southeast Asia, although they will not kill humans. Soldier ants are quite frightening too. In fact, the number of dangerous ants in the warmer countries can be disturbing.
Indeed, only a fortnight ago, my male dog was plastered in big red welts all over his stomach and under carriage. He was clearly in great pain when he walked and was off his food. It has been very hot here in Thailand this summer because the monsoon was late, so he most likely dug a shallow hole in the soil to keep cool. He was probably swarmed by ants while he was napping, but could not shake them off. He was in a very bad way for three days.
Some ants are vegetarians but others will happily eat meat, if it is on offer. Most ants will eat dead insects and small, dead animals. Some will also attack healthy animals, including humans, if they feel attacked.
One problem is that insects can become resistant to chemical controls and sometimes this immunity is localized, so it is better not to use chemicals if you can do anything about it. Chemicals can also present a hazard to children, which makes storing them and using them even more dangerous.
Boric acid is a by-product of boron which is a natural product. Boric acid is very good at destroying insects that take food back to their colonies, so this encompasses ants and termites. It can be mixed with sugar and water to make it more attractive to ants or can be spread around the garden with no danger. It is harmless to children and pets alike.
Cayenne pepper is another repellent-cum-killer. Grow your own cayenne peppers, blend them and add to boiling water, then spray over ants and ant runs when it has chilled. It will not eradicate a colony, but it will stop foraging ants.
Corn meal is a way of ant and cockroach control. Sprinkle it about and when the insects eat it, it will swell up with their digestive juices and cause them to blow up. Not very nice, but satisfying all the same.
There are other biological remedies for destroying or discouraging insects too, some are favourites of one country or local people. Why don't you ask around the older people where you live and find out what their parents used to use to control ants and other insects the natural way?