A group of Swiss professors have invented a device that checks whether or not a cow is in heat. It involves a body heat-measuring sensor that gets implanted in the genitals of the cow. When the sensor triggers (the recognition rate is about 90 percent), the farmer gets a text message so he or she can help bring the world more calves. A single device costs about $1,400, but modern practices to increase milk production have made cows increasingly display fewer signs of being in heat, so it may be cost effective.