soup writes
David (in Normandy) wrote:
This sounds exactly like a black insect we have here in Normandy -
this also arched its back in a menacing way - Devil's Coachhorse.
They can also run like Linford Christie on Speed!
Try this link:
http://www.essexwt.org.uk/species/de...e%20beetle.htm

Sounds and looks exactly right ,
http://www.rspb.org.uk/Images/devils...tcm3-60302.jpg
so should I worry about seeing one in the house?

You did the right thing in putting it out rather than killing it - I
think they're not very common.
--
Kay