Crayfish, also known as crawfish, or mudbugs, are freshwater crustaceans that resemble small lobsters and they can be found by many creeks, rivers, lakes or ponds. Crayfish can also be a good source of protein in a survival situation, the only problem is they are small and would require you to catch quite a few to make a hearty meal.
In this excellent 5 part video below BackyardBowyer shows you how to build a simple crayfish trap for Under five dollars using plastic hardware net, but this trap can easily be made by other scavenged materials if need be. So check out the video below and if you live by a creek try catching yourself some mudbugs and give them a try. Remember to check your states laws on trapping, every state has different requirements on trap types and trap material used.