Humans are not the only species that count. Seven animals doing genuine mathematical operations — with the caveat that "mathematics" here means "operating on numerical quantities", not solving algebra.
1. Crows: subtraction
Crows can track up to about 30 items, and will adjust behaviour if one "disappears" — basic subtraction.
2. Honeybees: the concept of zero
2018 study showed bees can distinguish "no objects" from "some objects" — one of the few non-human species to grasp zero as a concept.
3. Ants: step-counting
Desert ants count their steps to measure distance home. Researchers who attached tiny stilts to ant legs watched them overshoot their nest.
4. African grey parrots: ordinal numbers
Alex, a famous African grey, could correctly identify "which is bigger" between sets of up to 6.
5. Chimpanzees: short-term number memory
In some tests, chimps outperform humans at remembering the positions of numbered tiles flashed on a screen.
6. Cleaner fish: geometry
Cleaner wrasse can solve the "mirror test" — distinguishing their reflection from another fish — a hint at spatial-self reasoning.
7. Dogs: size constancy
Dogs reliably pick the larger of two food piles, accounting for both number and per-piece size. Rough arithmetic, in real time.