draw in one's horns

draw in one's horns OR draw one's horns in (manage with less money, spend less and adjust accordingly, become less active (e.g. in spending money)) — 1. присмиреть, умерить пыл; стушеваться; отступить, пойти на попятный, бить отбой; 2. начать жить скромнее (экономно тратить деньги)
An allusion to the snail, which when disturbed draws in its tiny horns (tentacles which bear its eyes) and retreats into the safety of its shell. See also come out of one's shell.

See also
[off one’s high horse]
[затянуть пояс]