Out of all the species of animals on earth, which is the most populated?

Yes, I mean all animals on Earth.

What about rats?

Good point. Probably some sort of crustacean, but most likely an invertebrate for sure.

No possible way. Humans haven't even reached 7 billion.

dude i thort there was like around 7billion people in New York

There's about 5 million in NYC, and the rest of New York state really isn't that heavily populated.

Yeah there are only like 6.5 billion humans on all of the earth. But at the exponential rate we're increasing it won't be much longer before we reach 7 then 8 then 30...

That is true, LS. At current rates of fertility, we may be looking at 100 billion people in the next century, and an impossible 134 trillion by 2250. Though most other animals will be extinct if that is the case, we will be outnumbered still by things like rats, tapeworms, houseflies, and tubifex.

Perhaps, but ants have like 9000 different species. If you take this knowledge into account, then we are not seeing their population in as great of a number as it is separated from one inclusive family classification and instead into thousands of species groups.

Insects are animals.

I think a better question would say creature not animal then it could be ants because ants are not animals there insects there is a difference thus it should say creatures.