A female hummingbird will usually lay two very small eggs which are about the size of a jelly bean or a pea. It is interesting to note that each of these eggs will be laid on different days. In spite of this surprising fact, the eggs will still hatch on the same day.
You may be wondering, how is this possible? Well, the reason for this is because the female will not start incubating the eggs until both of the eggs have been laid, thus allowing the eggs to hatch on the same day.
The incubation of the eggs usually last between 16-18 days, but it can take up to three weeks if the weather is cooler then usual when the eggs are laid.