Live in Philomath area in Benton County. Have been feeding sunflower chips in my hanging bird feeders. Late last week I saw (for the first time ever) my feeders being mobbed by dozens of what I think are some species of bee. The insects are fairly small (smaller than a yellow jacket) ; 1/2 - 3/4" long; not aggressive to me; have a bronze/brown "fur" tuft on their back; abdomen is yellowish with black bands. Insects appear to be "feeding" (both in the feeder feed cups and crawling inside of the feeder). During their "feeding" activity they kick out the largest sunflower chips. They continue until the feeders are completely empty (with a large pile of sunflower seeds/chips on the ground). I have also seen them (not as many) doing what looks like a feeding action on my mixed bird seed feeder. I am curious as to what type of "critter" this is and what it is doing, and any suggestions on how to keep them away from my hanging bird feeders.