They have started appearing for the last couple of weeks – day or night.
They appear mainly near the front door, but seem to travel.
I have a drain on the other side of the door, and it would appear as though they become more frequent after the rain (although it’s hard to tell, as it doesn’t seem to stop raining for long enough!)
They are also outside hanging out here & there on the white walls – again, only at the front.
They appear to be in two stages of growth when found. Some appear smaller & ‘younger’ – which are frantic & often on their backs, whilst others appear larger & more developed. The larger ones having more pronounced wings. The small ones are approx. 15mm in length, whilst the larger ones are approx. 20mm in length.
I’m pretty convinced they are coming from outside and are just ‘finding themselves’ in the house.
I have a brush strip at the bottom of front door but things could easily crawl under. The rear door is a tight seal.
I am currently collecting around 15 – 20 per day.
They are never near the kitchen or indeed the back door (also in kitchen) leading to garden – where there is also a drain.
Not sure how to stop them getting in the house. Pretty bored of scooping them up constantly!
The small ones could be, as Clive suggested, Rhagonyca fulva, the larger ones could be Cantharis livida. Fully developed (imago) beetles don't grow (individuals might vary in size, but that's another thing). Both are common, usually found in flowers and they are our friends as they feed on things that feed on our things.