by Mike Krumboltz Gender-bending frogs? 67-million-year-old snakes? Perfectly preserved wooly mammoths? These tale tales might sound like they come out of a comic book, but they're totally true. Frogs go from male to female When exposed to weed-killer chemicals, some male frogs develop female reproductive systems and the ability to lay eggs. Huh? The bizarre discovery was recently highlighted in a buzzy article from the Washington Post . In a study published on Monday,