What the Hell are These Things?

Ahh, hot weather. Which means ants inside the house. And outside, racing to find a way inside. Meanwhile, other insects swarm outside, waiting for their chance to come in -- and float toward the kitchen light.

Now, a new bizarre problem: These black specks, just a bit plumper than a grain of rice (and slightly smaller than a raisin), keep popping up under the sink in our kitchen. I must have sucked up around 40 of 'em through our Dust Buster yesterday. Any of you have any idea what they are?





I'm guessing larvae, but I'm open to your thoughts! (As well as how to prevent these things from over-populating the cabinet below our sink!)

UPDATE: Thanks to everyone for your comments. Indeed, I feel like the not-so-bright protagonist in a bad horror movie -- you know, the character who doesn't put together all of the pieces that are screaming right in front of him! Maria and I have noticed some shuffling sounds on our roof and in our walls recently... and thanks to a recent plumbing fix, there's currently a huge hole in our wall in the cabinet below our sink. The rat in question must be having a field day, hopping in and enjoying our trash (while leaving behind some poop pellets). I guess it's off to the Target to hopefully solve the problem... and yes, I better seal that hole as well.