A group of crows is called a murder. Well, only if there's probably caws. Only one or two crows is attempted murder. If you have a group of crows at church, it's a mass murder. If you have a group of crows and ducks together, you call it a murder most fowl that's not what it's quacked up to be.
What is it called when a shrimp kills another? A krilling spree!