You could spend your whole life studying ants and in the end feel like you'd only scratched the surface. For example, just in California there are about 270 ant species, including seed-harvesting ants in the genera Messor, Pheidole and Pogonomyrmex. There are honeypot ants in the genus Myrmecocystus and lots of carpenter ants in the genera Camponotus and Formica. There are native fire ants (Solenopsis), stinky Velvety Tree Ants (Liometopum) and some terrible introduced ants in urban areas which are eliminating the state's native ant species -- mainly the Argentine Ant, Linepithema humile.
At first all ants look the same. But, just look at these close-up pictures of ant heads:
And these, of the entire bodies:
These photos clearly show that incredible differences occur among the thousands of ant species. What the pictures don't show is this, though it's true: Behavioral differences among the many species are even more different and more fascinating to study than their anatomical differences!
To help you get started in the world of ants, first visit Antweb.Org, which graciously provided the pictures on this page. Also, check out these sites: