Lights on Backyard

I have noticed several backyards have flood lights on the back side of the yard. Is there any reason for this? So far I only can think of two:

1. mosqutos will go toward the lights and away from the deck.

2. Lights will point away from the neighbors so it will not disturb them.

does any of this make sense or I am completely of the mark?

By bobjohn | 09/12/2009 10:26 PM