Duck and Cover

Bert the Turtle says duck and cover.

A grinning monkey sitting in a tree dangles a lit firecracker from a fishing pole just over the head of an unwary turtle. Realizing that an explosion is pending, the turtle ducks and takes cover inside his shell just in time to avoid immolation from the explosion. As the scene changes to a picnicking All-American Family, a voice-over explains that in order to survive a nuclear attack, one must duck and cover.