Not for the squeamish
There are even bigger bloodsuckers still with us. Anyone squeamish is advised not to follow this link
http://invertebrates.si.edu/Features/stories/haementeria.html
Hollywood producers will be on high alert for the next Jurassic Park blockbuster script after boffins found fossils of giant prehistoric fleas. The monster bloodsuckers were thought to have used ruggedised straw-like mouths to prey on dinosaurs. In a study published on science journal Nature on Wednesday, University of Kansas …
The OP is probably getting confused with bedbugs, which I believe can be up to about 1cm. They have a probiscus to obtain blood, and they don't jump either - they just crawl onto their host and then go off to sleep on their meal for months on end.
Cue Rolf Harris singing "Tie me 2cm flea down, sport...".