http://www.sciencemag.org/news/2019/12/even-dinosaurs-had-lice-fossils-entombed-amber-reveal

An artist’s reconstruction of an ancient louselike insect on a downy dinosaur feather

As most parents of small children know, lice are survival artists, skilled at avoiding detection and spreading to new hosts. And now it’s clear they’ve had plenty of practice. New fossils found in amber reveal the insects have been around for at least 100 million years, when they feasted on feathered dinosaurs.