When animals choose mates, traits such as signalling are subject to evolutionary pressure.

I didn't know which animal to choose and neither did the robot.

The preferred walking speed is the speed at which humans or other animals choose to walk.

An animal like this one," he patted the sleek jaw, "chooses his own master.

It is also possible that some animals chose to ally themselves with the Mundanes.

We'll just have to make the best of it and hope the wretched animal didn't choose the best layers.

But the moan had not sounded like any cry that an animal would choose to make.

Why would an animal have chosen this route?

When a semitropical animal chooses to live in a cold climate, keeping warm is a primary concern.

That is why proteins (including meat) are such good sources of energy and why so many animals choose to eat it.