For fun, run around one in circles and make it dizzy - it's more fun than cow tipping. If one happens to get close, give it a good shove and watch it topple like your drunken Uncle Phil on Christmas Eve. Do not panic - these were only actors, with appliances designed to make the dancers look even more disfigured and bizarre than Jackson himself. If you encounter disco-dancing zombies, enjoy the floorshow from a safe distance. If you see Michael Jackson himself, know he will not give you money for looking at him.
Zombies are social critters.
Traveling with other zombies make zombies feel more intelligent. Which somewhat explains what Michael was up to in the first place. If you find yourself being slowly surrounded by zombies, calmly un-surround yourself. They hate when you do that. Don't hide in phone booths.