What is funny?

In the mountains in Colorado, my family and I went to my uncle's cabin. It is on the mountain side surrounded by forest and a huge lake in front of it. On the mountain side you could see the face of a bear. One time at the cabin, my Uncle Chuck, was repairing the deck over looking the lake. Me, my brother and my nephew was outside sitting down close to him. While he was lifting a piece of wood, it hit one of the birdhouses on the tree. The birdhouse fell to the ground, and out came two bats. At that time, me, my brother, and my nephew ran in the deck door, and closed it shut behind us. The only person that didn't get in was my Uncle Chuck because he didn't notice the bats. When he realized we ran into he start to think something was wrong. We told him, "look out for the bats!" He replied with, "what bats?!" He looked around, and he noticed the two bats flying around the tree where the birdhouse was. The bats noticed him running to get in, and when he turned back he saw them flying towards him. He let out the most highest pitch scream i've ever heard. The three of us who were inside the cabin started laughing. Chuck screamed to let him in, but we couldn't stop laughing. This whole time, he was running around in circles on the deck and the bats were right behind him. Eventually Chuck decided to jump off the deck to get away from the bats. We saw him jump off the deck and we burst out in laughter again and the bats swooped right down to where he was. We heard screaming right after and he ran to find a door that was open. He eventually made his way to the front door which was open, he opened it and ran inside and shut it quickly. The bats kept flying outside for a few minutes and they left. After Chuck caught his breath, we got in serious trouble from our parents for not helping him and just laughing the whole time. This was a very funny moment and i would love to see it happen again.