A few 100 million years ago, from the start tertiary era, the ants existed already. Their bodies were perfectly preserved, include in amber which is not other thing than resin fossil.

Some of these primitive ants were completely similar to the current ants of our gardens. Generally, the animals changed during centuries. The horse, or rather its old ancestor, was formerly not taller than a fox, and it was necessary million years to reach his current size and characters. The primitive birds had teeth and their wings were few developed ; modern birds are deprived of teeth and their wings are highly specialized. In fact such transformations constitute the animal evolution.

Some animals evolved much, others few, others finally completely disappeared. Animal species die if they can't adapt to changeable conditions of environment where they live, if they can't be protected from their enemies, find enough food or ensure safety of their young.

The study of length past of the Earth shows that geography and climate have undergoes many changes during ages. Marshes with the hot climate of there are 100 to 200 million years allowed the great development of the dinosaurs and this part of the secondary era is usually called the age of the dinosaurs. Those however died out before the following era. Because of changes of climate, some species could not find their food in sufficient quantities any more. It is possible also that eggs and young were anymore protect from terrestrial enemies lately appeared. Though it is dinosaurs extinguished.

Thereafter, during the glacial era, the enormous mammoths traversed frozen areas of north. They died out approximately ten thousand years ago. Like the dinosaurs, they were unable to adapt to the living conditions who change.

In frozen areas of Arctic, we can still find mammoths perfectly preserved in the ice.

But, from secondary Era to our days, no change of climate was enough important to obstruct the so resistant ants. No enemy succeeds to destroy them and the ants were always be able to find food and a shelter for their young. As much of other insects, the ants multiplied so much we can find them practically in all the areas of the  Earth. The most important fact is that, because their long and constant evolution, the ants had time to improve  their remarkable instinct.