Unlike most birds, hummingbirds do not sleep in nests. They prefer to find a safe place that will provide them with a good view of their surroundings and protection from predators. They will often return to the same spot every night until they are ready to migrate.
In order to conserve energy, hummingbirds enter a state of torpor at night. It is a type of hibernation that involves lowering their body temperature and heart rate. They will also fluff up their feathers in order to maximize the insulation they can get from them. As a result, they can look like a tiny cotton ball when sleeping.
It can be very dangerous to wake a hummingbird that is in a state of torpor. If you do not wake it within a few minutes, it may die from hypothermia. Therefore, it is a good idea to keep hummingbird feeders well-stocked in order to ensure that they have enough to eat each day.
Hummingbirds usually eat throughout the day and use their high metabolism to generate heat and energy. This means that they need to rest and recharge their batteries at night. Therefore, it is not unusual for hummingbirds to spend most of their time hanging upside down while they sleep. In fact, if you see a hummingbird asleep in this position, you might think that it is dead or sick because of the way it looks.
In general, hummingbirds go into a state of torpor about 30 minutes after the sun sets at night. However, they can sometimes decide to skip the sleep and continue feeding for a while after dark. They will generally feed in areas where there is plenty of natural light rather than glaring porch lights that might confuse them and disrupt their torpor.