Family Staphylinidae

[tersse]

i have recently found a beetle in my house and it has been wandering round for weeks, it was so large that i couldent find the heart to kill it, such a large beetlt i think takes a lot of investment of time and energy to produce, but after this few weeks i needed to find out what it was and searched the web.

it is a very large beetle some 1 1/2 to 2 centimeters long, it is completely black all over and very active as i see it allmopst evry night either in my bathroom, or running across the floor in my sitting room, these rooms are ajacent in my house but i think it actualy covers more ground than this, i allso have some very large spiders in my house though they tend to stay on the walls or even the celing, though i allso see the largest some 5-6 cm across running about the floor, so far they are both still alive, but is there any chance the spider might kill the beetle or vis versa if they meet as i wouldnt like this to happen, but as winter aproches i wouldent like to throw any of them out of the house as im in scotland and its getting prety cold now.

is it ok to just leave them be or is there anything i can do to help them survive the winter, if they can that is.

suggestions would be helpfull, though im inclined to just leave them be, and live their lives out as best they can.

i have searched this site and on other posts havew found my beetle, devils coachhorse or some such, the corect family and with it being so large i think that its that, it is a wonderfull sight and though on other posts ppl say it is agreasive this one has never raised its abdomen to me even when i cornered it to have a good look, it simply waited till i released it then went on its way, in a way i feel pleassed it dosnt see me as a threat and that it choses to stay in my house, i hope it can survive the winter, and perhaps find a mate and make more as it is quit beutifull.

[Wild-Woman]

Welcome to WAB tersse. Glad you didn't 'bump off' the beetle. It clearly sounds very at home in your house. It would be nigh-on impossible to id without a photograph however, but it does sound like you've done some research about it and may be hitting on the right family.If you're happy with it in your home, leave it be and it will probably make it's own way into it's natural environment.
As for your spiders, these sound like ordinary house spiders that are harmless and it will be males looking around your house for a female to mate with. If you leave them alone they will go about their business without problems then disappear until next Autumn.
Hope you enjoy it here on WAB.
Jules

[m1.carson]

Hi,

I've been watching devils coachhorse's at work, [very busy and overworked ], it looks like the common house spider won't touch them or cheeselogs, both have been right past the web, less than an inch away and the spider hasn't moved.

Max.

[Dogghound]

Staphylinus olens are around 2cm+ in size, there are so many staphylinidae species around, well over 1000 in europe that you would need a photo. Sometimes you would need more than a photo like microscope dissection.

[hsl]

It's nice that you care so much about this insect!

My friend lives facing a park that is all long grass with lot's of trees, and he's always getting giant beetles running across the floors of his house.

I've seen Devils Coach Horse's that must have been over 4 centimeters there. 1 of them had half a woodlouse in it's jaws and was holding it up like a shield! And 1 massive ground beetle that was about 3 centimeters that had a purplish colour and outline to it's shell.

[Paul mabbott]

It's interesting how we exaggerate lengths especially when we think somethings is a 'giant'!
It's easily done and few of us carry measures around with us.
I've seen a lot of Ocypus olens but hardly any above 3cms.
The ground beetle sounds like one of the violet ground beetles and would be about 2 - 2.5 cms.

We don't, unfortunately, have the seriously large beetles that are found in the tropics.

Originally Posted by hsl

It's nice that you care so much about this insect!

My friend lives facing a park that is all long grass with lot's of trees, and he's always getting giant beetles running across the floors of his house.

I've seen Devils Coach Horse's that must have been over 4 centimeters there. 1 of them had half a woodlouse in it's jaws and was holding it up like a shield! And 1 massive ground beetle that was about 3 centimeters that had a purplish colour and outline to it's shell.

[hsl]

You're right, 4 centimeters is quite big looking at it! I'd say it was over 3 though. But I promise you that the ground beetle was larger than what you say, if it's the same one. Well it was more than double the size of those common black ground beetles.

I have seen many insects that were considerably larger than they should be, according to the insect book I have

[Paul mabbott]

Originally Posted by m1.carson

Hi,
.............. spider won't touch them or cheeselogs, both have been right past the web, less than an inch away and the spider hasn't moved.
Max.

Okay, I've been thinking about this for hours ... I give in ... what's a 'cheeselog'?

[aeshna5]

Originally Posted by Paul mabbott

Okay, I've been thinking about this for hours ... I give in ... what's a 'cheeselog'?

I think it's a folkname for woodlice!

[lauriek]

Originally Posted by hsl

And 1 massive ground beetle that was about 3 centimeters that had a purplish colour and outline to it's shell.

That would be a violet ground beetle (Carabus violaceus), we've got one of those in the garden around 3cm, lovely little beastie!!