Traditionally the natural habitat of troll's was under bridges. Recently however trolls have began to inhabit many different locations because of the ecological destruction wreaked on bridge eco-systems. A recent evolutionary novelty is the Trollus Internetitus. The anatomy of the Trollus is mysterious as only few have met one in the flesh. The refuse they leave behind however is often written in a tone of knowing superiority and contains a statistically unusual number of CAPS and exclamation marks!
What this majestic creature craves above all else is doughnuts. Many are thought to undertake a long and arduous migration all the way from the forests of Red State and Free Republic in order for doughnuts feeding season. Trollus Internetitus should be provided with doughnuts liberally. However recent concerns have been raised that during the troll mating season (sometimes known as "election season" to scientific laymen.) it can be easy to mistake another species for a Trollus. This is dangerous as doughnuts are poisonous to all other known species.
There are many subspecies the most common of which I will discuss here. The kind hearted Trollus Internetitus Concernus believes in many different causes, but being a creature of conscience worries about the finer details of many of the ideologies it subscribes to. It expresses these genuine concerns and is best rewarded with doughnuts for it's civic service.
The Trollus Internetitus Disgustigus shocks it's prey with displays ranging from racism to sexism to awful images. Weakened and stunned the victim is forced to give the troll doughnuts. This type of troll exists in a symbiotic relationship with a host of personality disorders as well as bad character traits.
Trollus Internetitus crackpotus knows many terrible things. It barters this grim knowledge in exchange for doughnuts. As recent scientific studies have shown ( C.F Dennis Kunnich's groundbreaking research on the Rec list concerning vote counting.) it is very important to disambiguate between crackpotus and species who genuinely want knowledge and worry about the situation, lacking the omniscience of crackpotus.
Other subspecies are rumored including the astroturfus, the attentionseekus and the spammus.
Despite the destruction of its bridge habits Trollus Internetitus continues to adapt marvellously and is certainly not endangered. For example; even as other species suffer under global warming the Trollus Internetitus adapts, spawning global warming denial trolls. Truly we have many, many years of Trolls ahead of us. I for one am eternally fascinated by their variety, beauty and grace and if I have communicated a little of that wonder to you today I have suceeded.