Parasites are small - so there are probably many more parasite species than host species on the planet. The world is indeed riddled with life.
I have posted some mind control parasite videos before - to illustrate parasitic behavioural control in the organic realm.
There are lots of other interesting parasitism videos out there. Here are a few of them.
Warning: some of these are video nasties.
Jewel wasp vs parasite.
Moth ear mites.
Life in the Undergrowth - Intimate Relationships - butterfly, ant and wasp.
Toad with parasite in the eye.
Bot fly, housefly, cow.
Bot fly larvae in kitten's eye. This video is rather unpleasant. However, if you like it, there are other similar ones.