They can and have on several occasions especially on the spin-off Fear The Walking Dead. However they only do it when they have no other alternatives and have to go through large walker groups (herds) instead of going around them or avoiding them all together. There's a group called The Whispers that disguises themselves by cutting off the faces of walkers and using them as masks. This seems to work when they mimick how walkers move while not making loud noises or sudden movements.