They'd bite your head off before you finished 
While they're being shot at a diversion is created allowing enough time to tie their laces. Better still if they have velcro straps.

DO ZOMBIES SLEEP?
Posted by: ZRS Staff in PHYSIOLOGY February 8, 2011 11 Comments
It stands to reason that zombies must decay at a considerably slower rate than humans if they are to represent a credible threat to civilization. Now, ZRS Researcher Dave Cogan offers one compelling theory of how this longevity might be accomplished: Sleep.
Cogan sites a groundbreaking sleep experiment from the University of Chicago proving that after 30 days of total sleep deprivation, a seemingly healthy rat will drop dead. In fact, all complex animated creatures – humans, rats, sheep, cockroaches – need some form of regular sleep cycle to stay alive.
Sleeping Zombie
Sleeping Zombie
He goes on to suggest that zombies could slow their cellular breakdown by mimicking the survival techniques of the living. However, Cogan notes that this doesn’t necessarily mean a traditional, tucked-in-bed, eight hour recharge for our undead friends:
“Think of it as the standby mode on your computer. It hasn’t shut down completely, but rather is in a holding pattern, allowing the machine to last longer and run more efficiently when booted back up. Many insects and fish species act similarly, and so too may zombies.”
So the next time you spot a zombie milling about aimlessly, don’t just assume its too stupid or slow to do anything else. Maybe its just recharging so it can be refreshed and ready when the next tasty meal happens by.
Food for thought.
