Nightcrawlers are one of the most popular types of live bait to use for largemouth bass. Most nightcrawlers that are sold in bait shops will be about 5 to 7 inches long. Anglers will typically use hooks in the #2 and #4 sizes when they are using nightcrawlers. One of the nice things about using nightcrawlers as bait is that you can catch bass from 7 inches to 7 pounds with the same size bait. A live nightcrawler gives anglers the opportunity to have a lot more action because you may also catch bluegill, smallmouth bass, walleye, catfish, perch, rock bass and other sunfish.