Although their life cycle depends on deer, they may on rare occasions bite humans, producing responses ranging from unnoticeable to highly allergic.

Anaplasma phagocytophilum, a Gram-negative, obligately intracellular bacterium that causes anaplasmosis, has been detected in L. cervi, as has Borrelia burgdorferi, the causative agent of Lyme disease,[14] but whether the insect can serve as a vector is as yet unknown.

Remains of L. cervi have been found on Ötzi, the Stone Age mummy from the Schnalstal glacier in South Tyrol.

A newborn prepupa immediately darkens, forms the puparium, and begins to pupate on the forest floor, or where the deer are bedded.

[17] This species is found in most of Europe (including Great Britain and Ireland), as well as Algeria, eastern Siberia, and northern China.

It was introduced to and is established in the Eastern United States (New Hampshire, Massachusetts, Pennsylvania, Idaho, and New York).

[17][18] There are stray records of bites on humans, dogs[21] and badger, and it will occasionally commit to the wrong host.