bury (one's) head in the sand
To avoid, or try to avoid, a particular situation by pretending that it does not exist. The phrase refers to the common but mistaken belief that ostriches bury their heads in the sand when frightened, so as to avoid being seen. Lou, you can't bury your head in the sand about your health—please, make an appointment with your doctor and get that rash checked out! A: "How has Peter been handling the break-up?" B: "Oh, just burying his head in the sand and ignoring his feelings."