Do all mammals have belly buttons?

When petting your dog's belly, you might notice they lack a navel similar to your own. While mammals do have belly buttons, they're a little harder to find. Since mammals are gestated inside their mothers, they are all born with umbilical cords. read more

While mammals do have belly buttons, they're a little harder to find. Since mammals are gestated inside their mothers, they are all born with umbilical cords. When they emerge, the mother chews off the cord with her teeth, leaving a flat scar that is less noticeable than a human's navel. read more

Not all mammals have belly buttons. Placental (or eutherian) mammals have belly buttons. They nourish their fetuses by a placenta that is connected to the umbilical cord. read more

UCL researcher Stacy Hackner explains that all placental mammals, aka those that were nourished before birth in the mother’s uterus, start with a belly button. However, most of these mammals (and certain humans) have their navels obscured by fur, fade over time, or have a thin scar or small bump instead. read more

All mammals have belly buttons, the connection from child to mother in each mammal species. Mammary glands, live birth, and fur characterize mammals, but the placenta from inside the mother’s uterus and its umbilical lifeline to the developing fetus distinctly set mammals apart from other types of animals. read more