That's what we're trying to figure out. The mosquito nets used seem to be inadequate and I also get the feeling that they can come through under the doors as well. Every night before we enter to spray the sleeping room, I usually kill about 3-4 that are just sitting on the door waiting for us to open it so they fly inside.
This is our house in Lagos, not the one in the US BTW.
The funny thing is when I go to my grandparents village in the woods, there is zero mosquito and no need to spray the rooms at all.
The difference? No street gutter with standing water.
Ours is about the size of the one in the 1st picture, maybe a little less and it's not as close to our house as what you see in that picture. From my point of view I can't do anything about that breeding ground since it's outside our compound, so I have to stick to indoor methods.
Putting a mosquito magnet outside our compound near the gutter is just asking for it to get stolen, not to mention the Amazon reviews of that product are pretty bad.