Are human beings the mosy populous mammalisn specied? If so, most populous above insects?
There are estimated to be over 20 billion mice on the planet.
It’s estimated that there are 10 quintillion insects on the planet.
Mosy populous mammalisn specied? Maybe (but we have competition from the house mouse.) most populous above insects? Not even close.
But “mouse” and “insect” are not species. (“Mouse” probably isn’t even a cladistic grouping.) What is the most populous species of mouse, and what is the most populous species of insect?
Are human beings the mosy populous mammalisn specied?
Couldn’t you give a second look at what you’re writing before posting ?
According to this, there are over twice as many chickens as humans, and almost 100,000 times as many krill (Euphausia suberba) as humans.
Are all “mice” the same species, or is it a blanket term that covers more than one species?
Whar’s wrong with writing?
There are 8 words in the first sentence of your OP, 3 of which are spelled wrong. Four words in your second post, one spelled wrong. Some people object to bad spelling and grammar around here.
Hey, give him a break! He only joined 18 years ago.
Chicken aren’t mammals.
50% wrong in the first sentence, 25% in the second. He’s progressing.
According to this The tan bristlemouth fish is the most populous vertebrate on the planet, by an astoundingly wide margin. Like there’s quadrillions of the buggers swimming around in the deep ocean.
There are the odd *rattus norvegicus *around the planet.
They’d outnumber us by one, maybe two orders of magnitude.
Oh, the OP is asking about mammalian species. I thought he was asking about mammalisn species. 
The “tan bristlemouth fish” is the most populous as a genus, not as a species (there are 32 species says wiki).
Just a precision: dividing those trillions by 32, that fish may still be the most populous vertebrate on earth.
So what’s an Egg Cream then, huh? Explain THAT!
It’s still relevant to the second half of the question though, whether humans might be most numerous after insects*. The answer to that one being clear: no.
Among mammals it’s possible that getting technical about ‘species’ could put any single species of mice or rats (like Norway Rats, which exist worldwide) behind humans, or not. But mice, and rats probably, are more common types of animals than people, under the usual understanding of ‘types’ of animals if not technically ‘species’.
Rough answer without getting tied down in technicalities would seem to me: some rodent types have comparable or greater numbers than humans though not orders of magnitude greater, but loads of non mammalian types of animal are orders of magnitude more numerous than humans, far beyond insects.
*which as also noted before are not a species, but their numbers are so many orders of magnitude more than humans there’s seems little doubt single insect species also exceed the number of humans.
That’s the obvious answer. I thought everyone knew there are more brown rats than humans.