Yeah, they are always moving. I have a new appreciating for them. When I was a kid in the central Tx area, every once in a while, I'd catch a big black, wingless beetle that reminds me a little of these. I haven't seen those big black beetles in about 30 years. It might be a Rove sp but I'm not sure. I can't quite remember what it looked like. Back then, I was told it was called an oil beetle.
I just Googled "oil beetle". The pic I found looks like what I used to find. But not a Rove.
Hmm, I'm only seeing UK references. It would ooze a greenish, brown oily substance when picked up.
I just Googled that insect you're referring too. Nice looking insect. That's not what I have in my head though. I found what I used to see on the internet. Common name is Oil beetle or Blister beetle. Looks like they are in the genus Meloe. It was e tx, USA where I used to see them.