The transfer of heat by the movement of molecules which carry it is called conduction.

Here's why:

* Conduction: Heat transfer through conduction happens when molecules bump into each other, transferring energy. The hotter molecules have more kinetic energy (energy of motion) and when they collide with cooler molecules, they transfer some of that energy, causing the cooler molecules to heat up. This process is most efficient in solids where molecules are tightly packed.

Let me know if you'd like to learn more about other methods of heat transfer like convection and radiation!