Who can help me with this one? I was shown hundreds of these dead beatles in a basement in eastern Pennsylvania. They appeared suddenly, were active at night, and died by morning - mostly near a sliding glass door. The homeowner thought they were coming from the heating / AC ducts, but I can't confirm this. The AC / Heat was not turned on and hadn't been for weeks. Also, I found many more dead outside on a patio in front of a sliding glass door. The only near-by trees are pines. Unfortunately, I couldn't get a clear picture to post due to it's small size. Here's the description:
Shape similar to a small fungus beetle. 1/8" long, rounded rear abdomen/wing covers. Thorax rectangular(slightly longer than square)and about the same width as the abdomen, about 1/2 the length of the abdomen, and with no visible recess between the two. Viewed at 100X magnification: Antennae is serrate with 11 segments without club. First segment (near head) is about twice as long as the others, which are generally the same length. The head is small, black and mostly not visible from above. Thorax and abdomen are reddish-brown with light (not distinct) black patches. The black patches were not readily apparent without magnification. The thorax has one black "stripe" running down its length at center. Both wing covers have one oval black spot at about the center of each, running length-wise, and have a black rear tip. The thorax has tiny pits, the abdomen has lengthwise ridges, both only visible under magnification. The entire body seems to be covered with short hair.
Any expert want to take a stab? Thanks!