Buildings in Cambodia are not “tight,” that is, they are open to air flowing through, don’t have glass on many windows, etc. This picture is in my bathroom where a long horizontal “window”—actually a vent–is located in the wall above my bathtub. On the inside there is a screen to keep out bugs and birds and bats, but on the outside it’s a type of hollow-block design, something like small concrete blocks.
Some sparrows have built a nest in the block in the corner of this long vent opening. You can see straws and grasses from the nest protruding through the screen. A couple days ago their eggs hatched and now there are several baby sparrows whose silhouettes I can see jumping around behind the dirty screen.
I’ve started covering up my toothbrush and glass in case my guests are carrying any sort of bird flu or some such.
For another part of Cambodian trivia, notice the electrical wires coming out of the wall and not capped or sealed off in any way. Apparently some previous tenant had a hot water heater for the shower and took the heater with him when he left.