Why would an UAP use bright lights?

I had this thought today.

Why would an UAP use bright lights? I mean, we use it in our airplanes and helicopters to avoid collision and, hmm, to be identified but they can pretty much function without it.

Other thing is, all the UAP that was saw during daytime didn’t had lights on, right?

Anyway, I bet they can perfectly do their thing (whatever it is) without such space lights, or hmm, they do and we just see a really small percentage of UAP that use lights? (junior pilots maybe, haha)