The videos i saw ostensibly showed what looked like rear fixed wing aircraft, like a small f-16 or something. But you could only make out that detail from the lights, which can be configured however you want to configure them to look, so, technically, it could be a large quadcopter (or octa, or hex) with lights affixed that make it look like a fixed wing aircraft.
none of the videos i saw had sound from the drone to verify fixed wing or "copter".
regarding night flights, FLIR would work better for certain things at night ;-)
when i say FLIR i mean the things that militaries use, not the little doodad you plug into a cellphone or a handheld device with a screen and a camera. I was under the impression these things loitered much longer than any commercial quadcopter or normal battery powered aircraft. if my understanding is correct, that leaves two options - a glider, which is weight constrained so probably just a gopro or two, or a fueled aircraft, in which case, FLIR makes sense because that's a decent platform.
the reports were "flying around for hours" but that could be exaggeration and it flew a pattern several times over a couple of hours but was landing to swap batteries or whatever. IDK. I think this is all much ado about nothing.
The only openly available price I've seen for such things is from China, and then it's $80k. The Teledyne FLIR stuff is probably quite a bit more expensive.
Why are they only flying at night? To evade detection? Then why do they have lights?