Shoes squeak primarily because of friction between different parts of the shoe, moisture trapped inside, stiffness of new materials, or loose components. When parts like the insole, outsole, or the tongue rub against each other, they can create squeaking noises, especially if the shoes are new and stiff or if moisture has made the materials slippery. Additionally, walking on smooth surfaces like tiles can amplify the squeaking due to the friction between the shoe sole and the floor. Loose or poorly fitted insoles and worn-out shoe parts can also cause squeaks. Proper shoe maintenance, drying shoes adequately, and ensuring a good fit can help reduce or eliminate squeaking sounds.