Swarm creatures: Which are the best?

[Getsugaru]

As written on the tin. I am making a character who might go Worm that Walks, and even if he doesn't, he specializes in summoning swarms. This got me wondering what the best swarms are. So, Playground, what do you suggest?

[kitcik]

I will quote this from another poster since they said it all:

"Let me show you a neat trick. Look at the Dark Speech feat from Hordes of the Abyss. Open the Book of Vile Darkness and turn to the part about Hive Minds. Now go to the SRD and look at what kinds of swarms you can summon. Figure out how many bats are in a bat swarm and see if you can't figure out where this post is headed."