Answer Box direction

Hi.

If there’s no answers in a question, and someone write an answer, it appears under the answer box: http://imgur.com/8J0yBo1

But if there’s at least one answer, when someone write another answer, it appears above the answer box: http://imgur.com/TMuxgm6

It is a normal behavior?

I want always the answer box move down, like the second image. It’s possible?

Thanks.