Dr. Sawyer: If there was a specific time when all women were more sexually receptive, it could certainly streamline and maximize the efforts taken to have sex. Female dogs, for example, experience a surge of estrogen called “estrus” about four times a year, signaling that they are “in heat” to male dogs in the vicinity. Maybe the male-female mating ritual would be greatly simplified if a man could enter a bar, sniff, and say, “I smell estrus, come on, who’s ready?” Just a thought, but it could save time and several drinks! Human females don’t work this way. Theoretically, a woman should want to have sex most when she ovulates because theoretically, her body is trying to get pregnant. However, because humans have big brains that have a greater influence over sexual desire than simply hormones, research indicates that there is no one set time in the menstrual cycle when all women are more receptive to having sex.