How could they tell?
A Zombie Survival Army/Navy Store recently opened in Orlando, FL. It sells typical Army/Navy store stuff — camouflage jackets, ammo boxes, etc. — but it also features a pretty broad selection of supplies to help you survive a zombie apocalypse, such as MRE’s and first aid kits.
Although if you get a wicked zombie bite, I’m not sure a Band-Aid will help.
More usefully, they have a shit-ton of knives for sale.
Don’t think of it as a machete; think of it as a portable zombie guillotine.
So when the zombie apocalypse comes, head to Orlando to stock up on supplies. And trust no one.