[patton]

Yep. Mean, extremely poisonous. Hides in a hole, pops out, can kill a grown man.

[Eric in the Ozarks]

The guy who built our house had direct experience. His daughter was bitten on the upper arm by a reculse and the bite area refused to heal. It grew into a raw mess that no local doctor or hospital could control.
I finally suggested he ask for a referral to the Mayo Clinic in Minnesota and they were able to save the girl's arm.