It has become commonplace for pregnant women to undergo ultrasonography, or medical sonography, to check the physical health and progress of their unborn baby. A side benefit of sonography is the ability to detect the baby’s sex before birth. And the images, called sonograms or ultrasounds, became a child’s first baby picture. These are often shared with family, friends, and the internet, even if the baby is hard to decipher by untrained eyes. Sometimes those mysterious images invite pareidolia, which is our human tendency to see familiar shapes among the unfamiliar. See some examples of the strange things seen in obstetric ultrasound images in a list I posted at mental_floss.