Weird buzz from box in engine...

There is this weird buzzing noise coming from this box in my engine... It happens frequent like every 30 seconds or so for awhile after the truck is off and the key is out of the ignition... Does anyone know what it is??? Should I be concerned? One picture is the part where the buzzing is coming from, and the other is a diagram from inside the hood that shows the system the box is apart of....

 

Funny....I was in the garage the other day inspecting my new car when I heard this buzzing. I looked all over the car wondering what is making this buzz noise. I had not even thought the Taco could make that noise. I gave up, then about an hour later I was outside the garage (yes, the Taco sits outside for now) and I heard the noise even louder. I was somewhat relieved to find out my new car was not buzzing. Truthfully, I did not even look around the Taco for the noise source. It makes so many clunks, squeaks, and rattles I was not worried. I will be watching this thread though

 

Oh this thread is pretty old, I should have searched before I posted it because there is already a thread about it....

http://www.tacomaworld.com/forum/1st-gen-tacomas/43086-wtf.html

"It's an Evap canister. It takes unburned fuel vapors, and basically puts 'em back in to the gas tank, instead of the atmosphere. It uses a purge pump, which is the buzzing you hear"

 

Thanks

 

I have this buzzing too and didn't even know what that buzzing canister thing was. Thanks for the post! But looking at the photos, I think my evap canister is missing some parts - is that correct or does my 95 SR5 v6 not need the extra hoses? Anyone know?