My room had MANY mosquitoes in it when I checked in, so even though i was hot and tired, I waited in the hot courtyard for 30 minutes while they sprayed.
Once I returned to my room, within 10 minutes there were new mosquitoes in the room.
I went down and reported this the desk and got a lecture on keeping the windows and doors closed. It was 90+ F (33+C) that day, so this was just silly. Before bedtime I asked again about spraying and the guy at the desk laughed when I told him there were many mosquitoes in the room. (On his behalf, while this is unacceptable by western standard, I read that for Thai people this can reflect embarrassment.)
So my first night was spent swatting mosquitoes buzzing in my ears.
When I woke up the next morning, while sitting on the bed checking emails, I swatted and killed any mosquito passersby I could reach without getting up. (See photo.)
When I showed the photo to the front desk, they were properly appalled and went up with the cleaning lady to spray again. Unfortunately, the insects are getting into the room somehow and my second night was spent swatting mosquitoes.
I should have insisted on changing rooms the first night, but I thought spraying would help and then later I was too hot and tired to be bothered.
On the plus side, the staff was very friendly, the breakfast perfectly adequate, and other meals quite good with a nice price.