Many people wonder how robins find the worms. Most scientists now conclude that robins find worms by vision, thanks to experiments by an ornithologist named Frank Heppner. In his experiments, Heppner investigated all the robin's senses. Heppner established that vibrations, odors, and sounds do NOT help robins find worms. Instead, robins SEE worms inside their burrows or wiggling on the ground.
Robins cock their heads to improve their ability to look at the ground.
So, that's the answer to how robins find worms, but figuring it out wasn't easy. Several students from Ms. Sheer's fourth grade class at Glenwood School in Chapel Hill, North Carolina, pondered this question long and hard and came up with some fabulous experimental designs. Some were exactly what Dr. Heppner had thought of, and some would make fascinating experiments on their own. The tape recorder catches the noises and puts the noise near the robin. It might hear the little noises and go down and look at the tape recorder, thinking it is a worm.