When does a dog sleep? You think it a silly question. But in my opinion and as per my observation dogs have particular periods of sleep. No, I am talking about strays.
Stray dogs think that they are responsible beings, responsible for the protection of the house at the doorstep of which they move regularly. They get something to eat from there.
So they spend long hours in protecting that house. Evenings are busy human hours and at that time there is no danger for human. So dogs sleep during these hours. Nights are vulnerable because humans sleep during nights. And dogs remain awake to protect them.
Dogs, yes stray dogs sleep during dusk the time of maximum human activity. They remain awake and active watching all the nooks and corners of their colony, I mean human residential area.
When it is four to five in the early morning humans start moving. And this is again the time of these dogs to go on sleep.
Dogs do their duty and this they remain proud of. Sometimes you may have seen that you are walking on foot to somewhere and a dog too is walking gracefully behind you showing that he is walking behind his owner, though you don’t recognize the dog.
When you look back and see that the dog too is walking behind you, you are irritated and stop suddenly to scold the dog.