Chigger

Chiggers are the larval stage of mites in the family Trombiculidae, found in grassy, wooded and humid environments worldwide, where they climb onto passing hosts such as humans, birds and other mammals from vegetation. Unlike many parasites, the larva does not feed on blood but instead injects digestive enzymes into the skin that break down cells for it to consume, causing an intensely itchy welt at the feeding site, and once it has fed it drops off the host and molts into a free-living, non-parasitic nymph and adult.