No pic. Try posting it in the comments and wait for the image to turn from gray to clear. Also, the image may be too big for Houzz and might need to be resized if it still doesn't post.

tj

John:

I've found that leaking sinks are common and leaking sinks make for perfect bug habitat. Do you have brown gunk at your undermounted sink that won't stay away? If so, your sink is leaking and must be remounted. If so, bugs are the least of your worries as you're flirting with a blown reinforcement rod if your sink is leaking and your tops are stone.

Silverfish?

Cockroaches another possibility, as well as earwigs.

If they are tiny bugs, it could be the oddly named book lice.