Black ants keep appearing in my bed?!?

I keep finding black ants in my bed, they bite and it hurts, they are not small like sugar ants and vary in size from tiny to pretty big, we've changed our sheets but they still keep popping up! We have laminate floor, we've swept, mopped, disinfected. We don't eat in the room or bed. The ants seem to be in blobs, they don't travel in a straight line and we can't tell where they're coming from. we've set the sugar traps on the floor but they just don't even go down there. We don't know what else to do, we're totally stumped... can anyone help?!