Abstract: A device and method for use in a farrowing pen, the device comprising a housing, first and second mounting members for mounting the housing member on a farrowing pen, a blower mounted in the housing, an air inlet and air outlet formed in the housing to make air flow to and from the blower, a motion detector, and a control circuit operative to operate the blower when motion is detected and to stop the blower when motion ceases. The device is arranged such that the motion detector will detect the presence of the sow in an upright position and the control circuit will operate the blower, while when the sow is in a prone position, the motion detector will not detect movement and the blower will not operate.