shrimp fight?

I just got two japanese algae eating shrimp yesterday, and I found one dead in one of my decorations and the other is nowhere to be found. I don't think the fish in my tank couldve eaten an entire shrimp overnight though. I have 2 balloon mollies, female beta, and a black molly. Could these guys...

Hey all :) I've been MIA for a tiny bit but all has been so great with my tank (knock wood) that I've kinda put attentions elsewhere. Anyway...super weird behavior caught on video of two dwarf shrimp (neocardinia) one red and one blue (both male...only have males in my tank 5 and one amano)...