This bug caught my wife's eye late last nigt on our wooden floor. It is circa 2.5 cm long.
Please can you help me identify it?
A rove beetle, no idea of species. Rather squashed!
Try Staphylinus olens, see http://en.wikipedia.org/wiki/Devil's_coach_horse_beetle. Size seems about right.
Mind you, that might not be the exact one as there are many species and they probably all behave like that!
Perhaps one of the experts could confirm.
Anyway they are harmless, even though the popular name is "Devil's coach horse".
Sorry, folks, you are unlikely to be able to identify this beetle to species from photographs. There are around a thousand British species in the Staphylinidae and many require dissection to identify. There is a small clue in the pictures - the first 3 antennal segments look very long compared to the others. This might narrow it down a bit.