Why does a dog circle its bed before lying down scientific method steps you would take

The scientific method is a method in which scientists have to follow predetermined steps in order and check if it presents the expected result or not.

In this case, first of all, is to recognize an objective or the problem and according to the question that is "why does the dog circle its bed before lying down".

The second step is the observation to get prior exist data, like if only occur around a pillow or any sleeping area or is it common.

Next step is to present hypothesis or an idea why does the dog do it,

So hypothesis is that dogs don't have pillow always and they had to sleep in ground so they have to move around to check and make it comfortable for laying on it.

the correct answer is:

a population changes in response to a change in the environment.