Weird bat glitch

So this is the latest update in case I did the wrong one. I placed a bunch of every type of flower on a smallish island. I have a half-built house and a small wheat farm and I am on survival Peaceful. I noticed a bat flying around and I was curious, as there was no cave system in sight, or on the island at all. I went over to collect some sugar cane later and found about 6 bats in a perfect part of a circle surrounding part of my island. I have also noticed an abnormal amount of squid, so maybe a mob glitch.