Red worms look similar to nightcrawlers, but they are smaller and skinnier. Red worms are mostly used to catch perch, bluegill, rock bass, trout and other panfish. When fishing for panfish, red worms usually work better because of their size. A bluegill can easily get a red worm into their mouth which gives you a good chance of setting the hook and landing the fish. Red worms can be found in most places that sell nightcrawlers – bait shops, gas stations and super markets.