Q. When we studied high school biology, our teacher said more than 99 percent of animals lay eggs and only a few give live birth. That percentage seems too high. Humans, dogs, cats and cows are ...

Despite their underwater habitat, whales are mammals. Mammals are not solely terrestrial; some, including whales and dolphins, are fully aquatic the University of Michigan Museum of Zoology reports.

Q. When we studied high school biology, our teacher said more than 99% of animals lay eggs and only a few give live birth. That percentage seems too high. Humans, dogs, cats and cows are ...