How can airport scanners see marijuana?

Smell and x-ray.These scanners have very sensitive smell receptors that can pick up the slightest trace of marijuana and other drugs, even if they are stuffed in your bottom.

X-rays can detect drugs in luggage.

Airports also use sniffer dogs to detect drugs and other contraband.

Some even use hand-held boxes full of bumble bees (seriously, bees can be trained to go crazy if they detect drugs).