Out of curiosity...

[Origomar]

Is there any way to create a character that soley survives on controlling thousands of small woodland creatures?

Think squirrel girl vs doctor doom. Or starcraft zergling spam. There are so many of them there is just nothing you can do.

Any feats that would allow the control like leadership is for humanoids and undead leadership for well undead?

I sincerely doubt it would cost that much to control one small woodland beaver or squirrel.

[Quietus]

Leadership could, in theory, give you squirrels as followers. And you could replace them easily enough, it says so right there in the feat's description.

Otherwise, use 3.0; That's how animal companions used to work.

[Pharaoh's Fist]

Swarms. Darkspeech. Hivemind.

[Origomar]

Swarms. Darkspeech. Hivemind.

What exactly do those do?

and does anyone know where i can find a squirrel in a monster manual?

[Pharaoh's Fist]

You're really going to have to check the BoVD for this one. I can't transcribe all of it, but look closely at the Vermin Lord PrC and the Darks Speach feat.

[SethFahad]

and does anyone know where i can find a squirrel in a monster manual?

Actually there is something...close to squirrel. Monster Manual IV page 126 the Skiurid (tiny magical beast extraplanar) from the plane of Shadow.

[Teron]

Use rat stats; just remove the swim speed from single rats, and the filth fever from swarms.

[Tiki Snakes]

You could always take the hardcore route.

Pump handle-animal to the stratosphere, spend months and months in-game catching, training squirrels for war.

Unleash them en-mass, buffed or otherwise. If you've caught enough, the sheer number of individual attack rolls should guarentee plenty of critical hits.

Of course, anything with damage resistance of any kind will be pretty much safe, and you'd have to take months out in between fights as you re-stock your army... ^_^

[SethFahad]

Use rat stats; just remove the swim speed from single rats, and the filth fever from swarms.

plus add climbing speed 20ft.

[Teron]

They already have a climb speed equal to their land speed (15 ft.), actually.