Brains of Tiny Spiders
The brain is near the head because of its proximity to the eyes. Because eating is critical to survival, animal focus their eyes and other sense organs near their eating ends.
from It's Okay To Be Smart
Key Facts In This Video
The first organisms on Earth didn't have heads or brains but could differentiate between right and left. (0:44)
The brain is near the head because of its proximity to the eyes. (2:26)