Why do wheels of vehicles spin at one spot in mud?

Wheels of vehicles spin at one spot in mud due to a combination of insufficient traction and excessive torque. When the tires encounter mud, they may not grip the surface effectively, causing them to lose traction instead of propelling the vehicle forward. As the vehicle's weight pushes down, the tires can sink into the mud, making it difficult for them to gain enough grip to move. Consequently, the wheels rotate in place rather than advancing.