It is a little difficult to identify through the photo- might need some more information like:
Do they jump?
Are they biting?
How big/small?
Was this due to a recent high tide that would have covered the dock?

It would be even better if I could get a sample to take a look at under a microscope; if you can get it to either the Talbot Extension office (or at least Caroline County office), I can take a better look.
-Mikaela
Talbot Co Extension Office
28577 Mary's Ct.- Ste 1
Easton, MD 21601

they crawl, no bites that we see, their tiny , kinda whitish, and we didnt have a dock covering tide. Their is swallows nesting under the dock , wondering if their some sort of mite?

Bird mites might be a possibility, then; we couldn't really get a sense of scale from the photo. They can leave a nest and wander if the bird hosts are finished nesting (such as when nestlings fledge), so that might explain their somewhat sudden appearance. Hosing or sweeping them off should suffice, though without a food source, they may also just die off on their own soon enough.

Miri

Jim-

They also looked like mites to me, but difficult to diagnose via photo. Bird mites are a possibility and might explain their appearance. Without a food source, they should not survive for very long. Hosing or sweeping them off the dock should take care of it.

You may see them periodically with the swallow nests above, but if they continue to be a constant presence, you can bring a sample into the extension office and we can take a look under the microscope for further examination.

Thanks-
Mikaela

Thank you
Sent from my iPhone