Hamster crossing.
As you may know, both humans and hamsters have 46 chromosomes. One common technique of cell biology in the 60s/70s was “cell fusion” of hamsters and humans to produce so-called “Hum-ster” cells. This sign is simply fulfilling the Federally mandated Community Warning required by the Godless Interference with All that is Right, Decent and Innocent Act [GIARDIA] and Local Angry Mobs Burning Laboratories and Investigators Act {LAMBIA - or “the Frankenstein Act”]
You will also see signs like these: [link]
[Yup. I’d say "Giardia Lambia pretty much covers the content of this post.]