what exactly are they?

ok i need this answered :)...

what exactly are...BATS...?
i mean are they birds
or like rodents?
its been bugging me.
i mean it flys so its a bird right
but i dont think they lay eggs.

its a mammal..
ugh
ok
i think im gonna make a new species..

and i shall call it..
Mammirdie
(mamal-birdie)