A square-shaped locking mechanism is used to attach a device on a wire grid. The locking mechanism is slightly smaller than openings on the wire grid. The locking mechanism is passed through the grid until indents between the locking form and the cylindrical container are in the plane of the wire grid. The cylindrical container and locking mechanism are rotated 45 degrees, until the wire grid becomes trapped between the device that is being mounted and the corners of the locking device. This locks the device in place. This locking mechanism is particularly useful for securing bait containers inside fishing traps. A novel bait container is a cylinder with halves that open on hinges. The container has mechanisms that ensure that the container remains closed during use and has features to improve grip during operation.