A teat locating sensor for use in farming equipment such as robotic milking machines and teat disinfection units. One or more cameras capture an image of the udder. The captured image is processed by applying an edge detector to provide an edge image. A Hough transform is applied for detecting edges using semi-circles and near vertical forms. A feature detector then matches these to provide teat ends and teat sides and thus produces a teat location map. Colour or monochrome cameras can be used and a 2D or 3D map can be generated. Filtering is described to improve the accuracy if required.