Lawn mowers and attachments for lawn mowers are provided. An attachment includes a body including one or more sidewalls defining an internal volume configured to receive clippings from the lawn mower, wherein the body defines an opening; and a cover coupled to the body at the opening and moveable between an open position, whereby the opening is open, and a closed position, whereby the opening is closed, wherein the cover is selectively lockable in the open position, and wherein the cover is biased to the closed position by a spring.