Initially thought these were moths in flight, but when settled could see the wings had hairs on them and the long antennae
No interactions present.
I'm fairly sure this is not Glyphotaelius pellucidus - that species has more granular shading on the wing, and has small spots along the edge of the wing tip. The wing markings are a very good match for my specimens of Limnephilus lunatus, and I think this is one of the more distinctive of the caddisflies, but I don't have specimens of all the other 29 Limnephilus species, so can't be certain that there is no other candidate.
The key to caddisflies (by Macan, 1973) distinguishes the species by the structure of the genitalia - this can often be seen at the tip of the abdomen without dissection, and in theory could be photographed if you are able to take detailed close-ups, but in most photos the wings cover the abdomen and preserve their modesty.
The 'spurs' are paler brown and slightly larger than the black 'hairs' on the legs, but they're not easy to see in photos unless the lighting is just right. I can just about pick out the four spurs on the hind leg in your first photo.
Entomologist and biological recorder
This has a marked scoop out of the rear margin of the wing and no lunar mark.
A few other species have a lunar mark but a clearly marked off pale lunar mark and other strong marks is characteristic - unless you live in Highland Scotland when you need to beware borealis and subcentralis.
Ian Wallace, UK Trichoptera Recording Scheme
Lat/Lng: 52.8, 1.2
OS grid ref: TG1830