foul one's (own) nest(redirected from foul their nest)
foul one's (own) nest
To do something that creates problems for oneself. I wouldn't talk to the boss while you're angry—you'll just end up fouling your own nest.
foul one's own nest
Fig. to harm one's own interests; to bring disadvantage upon oneself. (Alludes to a bird excreting into its own nest. See also It's an ill bird that fouls its own nest.) He tried to discredit a fellow senator with the president, but just succeeded in fouling his own nest. The boss really dislikes Mary. She certainly fouled her own nest when she spread those rumors about him.
foul one's nest
Also, foul one's own nest. Hurt one's own interests, as in With his constant complaints about his wife, he's only fouling his own nest. This metaphoric expression transfers a bird's soiling of its nest to human behavior. [Mid-1200s]
foul your own nestLITERARY
If someone fouls their own nest, they do something which harms themselves and damages their chances of success. Man has invented a hundred ways of fouling his own nest — the grime, the pollution, the heat, the poisons in the air, the metals in the water.
foul your own nestdo something damaging or harmful to yourself or your own interests.
The proverb it's an ill bird that fouls its own nest , used of a person who criticizes or abuses their own country or family, has been found in English since the early 15th century.