A mite which becomes a foot
Descriptions: Macrocheles rettenmeyeri is a rather unusual parasitic mite which has is dependant on ants as hosts. The bizarre thing about this mite is that it replaces the tarsus (foot, but analogously only) of ants. That;s right it literally bites into the tarsus and latched on the the end of the ants leg feeding off the ant's haemolymph (blood, but analogously only). It operates as a perfectly functional tarsus, and may even improve the function of the leg. Not much is known about these guys, and pictures are hard to come by, and there is pretty much just one doing the rounds:
So I got you guys an illustration from a journal article:
Don't say I don't look after you.
Macrocheles rettenmeyeri have been found in army ant colonies in Panama.
Species: Macrocheles rettenmeyeri