I have only seen one in our house. We had both doors open to cool the house and one waltzed in and climbed up my hcbw's ankle. She kicked it off without getting stung.
My dog got stung on a walk at night and went down like a sack of potatoes. He never yelped. He finally struggled to his feet without being able to use his left front leg, but it was really awkward looking. I carried him home and he started getting some feeling back about four hours later.
The bark scorpion has an impressive neurotoxin. I know it is just a matter of time before I get hit.