It depends on the betta and on the cover you give your shrimp. I have my betta in with snowball shrimp and am sure he occasionally gets a baby shrimp for a snack, but the bottom of the tank has a good 1 1/2" layer of java moss on it. It is just kind of floating about 1/2" off the bottom. I didn't attach it to anything. The shrimp are all over it until my betta gets close. Then they scramble down below where they are much quicker than he is. He tries to get them, but I have never seen him actually catch one. Out in the open water though, bettas can strike pretty quickly if they choose to.