My question is,does anyone play multiplayer worms?If so, which game has a bigger comunnity Worms 3D or Worms Mayhem?

Worms 4 Mayhem by far. There's barely anyone in Worms 3D.

And Worms 4 is much better in that aspect anyway. (And, lets face it, almost every other aspect)

Thanks,can you also give me an estimate of people on multiplayer at peak times?

Hmm, I'd say maybe twenty five to thirty five people.

In worms 3d i can say you the names of players who play there... xD

Some people of PKS:
Roman
Clooney
Lancast (he also plays or played W4M

Some people of [PRO]
Grenadex
AlexBond (the worms 3d, script hacker who only does maps ^^')

Some People of [CDR]
N2k2
XXVI
And maybe riquelme, kalimoxo, Brian and ALpha P8 will coming soon

Othe people:
Worminator, Terminator, Andruschka etc...

If you wanna check this out... http://worms3d-portal.com/ ;)