These are bedbugs. You should contact a pest control company to exterminate these. You don't want these around your house.

This may also be a 'batbug' which looks identical to a bedbug except under a microscope. (search the web for some comparison photos which show the minor differences on the head). batbugs are bat parasites which congregate where bats roost, which may be behind your shutters (as they do on my house) or in your attic. batbugs live inside the walls, hibernate in winter, and can live up to a year without feeding. We found their casings between our windows, around door openings, and live ones even walking in our bedroom. i found the live batbugs had dug huge holes in the mortar behind our shutters and were over-wintering there.
whether bedbugs or batbugs, you should attack this pest aggressively.

Please do your homework first, so you won't get taken by an unscrupulous exterminator. An excellent start is: http://www.hsph.harvard.edu/bedbugs. Good luck!