I have these huge black ants coming into the house. Are these harmful? Are they wood ants? They've been coming in the house since it's been raining every day for the past 3 days. I have a 1600 sq. ft house and I'm finding them everywhere, not just in one certain area. I turn around and there's one on the carpet, then I walk into another room and there's another on the carpet. I walk across the house and there's another in the master bathroom.
It is possible that this is a carpenter ant (Camponotus spp.), but I cannot tell for certain from the image. Carpenter ants may be distinguished from other commonly encountered household species by the smooth curve of their thorax when viewed from the side. In other household ants, there is a definite suture that interrupts this smooth outline. Also, (and this can be seen only under magnification), carpenter ants have a circlet of setae at the tip of their abdomen. See http://tinyurl.com/2r8mmp for more detailed information.
Here's a different picture.
