Some ingredients that clog rabbit ears also seem to clog pores in young Black men’s skin when left covered for a month, so rabbit tests might help guess which products could cause breakouts in people.

Rabbits’ ears get clogged more easily than human skin when tested with the same products, so the rabbit test might be too strict and flag things that don’t actually clog human pores.

If a product doesn’t clog rabbit ears much, it’s probably fine for most people’s skin — but if you’re the type who gets lots of blackheads, it might still cause problems.