My 11 year old son asked the following question and I wondered if anyone knew the answer: If a leech enters the nose or ear openings, is it possible that it could reach the brain and possibly kill you by sucking out necessary blood flow?
No. In either case, there’s a barrier between the brain and the outside. The ear has the eardrum, as well as all of the parts of the inner ear, and the nose has a barrier as well.
Maybe what he heard about was the brain infection you can get when exposed to the ameba Naegleria. That enters the body through the nose and gets into the brain! Don’t get warm lake water up your nose!!