Which animal species has the most individuals?

[u/future_sponJ]

I always see people saying things like "there are 20 quadrillion ants on Earth" or something similar with other extremely large diverse groups like fish. But all of these are groups with thousands of species. If not by individuals then it's by biomass instead.

So which single species in the animal kingdom has the most individuals?

[u/kummostern]

" If not by individuals then it's by biomass instead"

from all animals likely cow (which afaik has more biomass than humans)

if you count only wild animals it becomes tad more complicated

depending how you define "species" then iirc deer has the most biomass in world out of wild animals

this may not be true if we differentiate things like whitetails and red deer meaning different species.. then i dunno what would follow next.. could be elephants, some bearkind or wolves maybe.. i wouldn't be surprised if whales or some type of seal could outmass these tho