How can you tell when a Guppie is about to give birth?

There are a few ways to tell if a guppy is about to give birth. 1. She will be hanging out by herself near a densly populated area, corner or by the heater or filter. 2. A male will not leave her alone so that he could be the first to mate with the female. 3. She will reject food. Watch her behavior when you feed the fish.