Unless you leave food out and attract them, humans rarely have a need to think about ants. They're tiny, not poisonous and not particularly terrifying, like say, spiders. However, they far outnumber humans on earth--by one million to one!
Funnily enough, they are also roughly a millionth of a human in size too. Do the math--the total weight of all the ants on earth matches the total weight of the entire human population.
There are 10,000 different types of ants and they've been around for a long time. Ancients ants have been discovered in fossilized sap from 100 million years ago!