Is anyone able to identify the insect pictured below? We have found dozens of them around our new house, in most of the rooms. This is one of the larger ones, about 2mm long. Most are smaller and more pale, probably at a younger stage than this one. I have attached 2 photos, including one of the younger insects, if that helps.
We have no children or pets, but would be grateful for any help identifying the insects, and whether we should be overly concerned.