1) Hanger is when you get angry because you need more food. Your brain panics when it doesn't get enough glucose because food has the glucose that your brain needs but you aren't eating enough. 2) Your brain sends instructions to other organs in your body that release hormones to increase the amount of glucose in the bloodstream. 3) Our ancestors might of always let other people get the food first so they would go hungry.

1# Hanger is when you get impatient or irritated when you don't have enough glucose because you haven't eaten enough. The brain panics when you don't have enough glucose because the brain rely's on glucose so when the levels are low it panics. 2# The brain sends instructions to organs to release a hormone giving the bloodstream more glucose . 3# Scientists think hanger could be genetic because they said "If our predecessors just stood back and politely let others get to the food before them, there is a good chance that they may not have gotten enough to eat, and they would have died."