Jigger
Jigger, or Chigoe, a small tropical American flea. It is about 4/100 of an inch (1 mm) long. The female burrows under the skin of barefoot persons, causing a slight itching followed by a painful ulcer.
The name jigger is sometimes also used for the chigger.
The tropical jigger is Tunga penetrans of the family Sarcopsyllidae and the order Siphonaptera.