My boyfriend bought me 3 ghost shrimp to put in my 5.5 gallon tank last night. At first my betta seemed fine with them but when I woke up this morning my poor betta's tail was torn up. I thought it was tail rot at first. I went to work and when I got home, the tail looked worse. I saw a shrimp swim to the top of my tank so I tried putting some freeze-dried blood worms to see it's reaction. My fish immediate went to eat it and the stupid shrimp bit my fish's tail. My poor baby tried swimming away but couldn't and a chunk of his tail ripped off. I immediately took the shrimp out of my tank and killed them.
I highly suggest you don't add stupid ghost shrimp in your tank.
It's so not worth it. Although they are super inexpensive, they are not worth the money. My poor betta is now missing 3/4 of an inch of his once beautiful tail. Hopefully it grows back to the same length. The past 24 hours has been way too stressful for him. I hope he recovers soon.
I'm sure it is different with every fish and tank. I guess it just didn't work out with mine. Just be very careful and observe your tank when first introducing the shrimp in. Also, make sure they are well fed and are the right kind of shrimp. There is a type of shrimp that looks almost identical but known to be more aggressive.