A common phrase referring to innocent people entering into danger without realising it.
The phrase comes from the traditional children’s tale of The Babes in the Wood, first published anonymously in 1595. The story features two young children who are left to the care of their aunt and uncle when their parents die. Abandoned in a wood, the children die and are covered with leaves by a robin (in later versions they are then taken to Heaven). Unlike many similar tales of the period, the story does not finish with a redemptive moral ending.