I work at an animal hospital
These were removed off a cat that was infested with fleas.
Wings are longitudinally folded
The pronotum hind margin is U shaped
Short antennae
Pronotum does not extend beyond the base of wings
When collected was very dark colour almost black. Caught right outside my house.
Found in rotting downed tree when I pulled the bark off.
Typical rolled into a ball as a defense mechanism.
Identified using bus guide, specifically following this classification https://bugguide.net/node/view/55219/tree