So thoughtful

My office area and the surrounding location have quite a few trees. The suntec mall management has hung some bird cages with singing birds. Its a real pleasure to listen to these birds. Some of these birds are inside the mall. Since the mall is usually lit throughout the night, I used to wonder how these birds differentiate between day and night. The other day, I noticed that when the sun sets, the cages are covered with a cloth cap so that the light doesn't disturb the birds. I was pretty impressed by the thoughtfulness.