Cricket, Katydid, or Grasshopper?
Having determined how to tell katydids from crickets and males from females, the next step is to make a general distinction between katydids, and grasshoppers (which are sometimes confused with katydids). Cicadas, like katydids, also “sing." Some grasshoppers make short, buzzing sounds with a leg against a wing, but these are not as repetitious or "musical" as crickets and katydids.
Grasshoppers, katydids, and crickets are all members of the order Orthoptera, and I’ll present the general information you’ll need to separate them. You can find more detailed structural information in the resources I’ve recommended, but I’m going to focus on field identification and songs. You’ll find all three in a variety of habitats, so you’ll want to be able to quickly separate the grasshoppers.
Crickets and katydids are members of the suborder Ensifera, and they have very long antennae. Look at the antennae of a grasshopper (suborder Caelifera); they are obviously much shorter. In addition, the grasshopper’s legs appear much more powerful in comparison to those of katydids and crickets.
For example, the Gladiator Meadow Katydid and Northern Green-striped Grasshopper can be found together in the same habitat. Look at the antennae. Look at the legs. Got it?
You’re much more likely to confuse a grasshopper with a katydid rather than a cricket with a grasshopper, so let's try another katydid/grasshopper comparison. No, I'm not giving you the answer.