1) that leeches merely double in size when they feed (they can increase 5 times their weight or more).
2) that leeches raised in captivity are "sterile to a certain degree" (all leeches, wild or farm raised harbour Aeromonas in their crop; a course of antibiotics is recommended during post-operative leech therapy)
3) that they quickly attach and start feeding (far from true, especially in North America)
4) that leeches hold on with rows of tiny teeth (they hold on with their suckers, the teeth, far too small for holding onto anything, and which do not meet in any kind of bite, are used only for making incisions)
5) that removal of leeches requires one "to rip the teeth away from your skin" (in fact all that is needed is to gently break the suction seal made by the oral sucker at the smaller end of the leech, once that seal is broken, the leech cannot hold on and can be readily removed by detaching the posterior sucker)
6) that is will not hurt "because the leech has injected a numbing agent" (see my previous post about this unsubstantiated myth)
This is all timely in light of Carl Zimmer taking to task George Will and the Washington Post for failure to fact check on science. Alas, some science writers too fail to fact check. Please note that Discover Magazine where Carl is a columnist has no relationship with Discovery Communications where Brain blogs about "stuff", like