Visit the largest colony of bats on the planet in Texas, discover the surprising habits of South Florida's sharks and see Arizona's scorpions do fascinating things with ultraviolet light.

Bison thunder across America's plains during the world's largest bison round-up in South Dakota, while bald eagles fly high at a Maryland dam during a feeding frenzy. Meanwhile, step back in time to America's last fully operational mule train, and then head to a quirky town in Alaska to meet the quirky mayor – a cat named Stubbs.

Come winter, manatees gather by the hundreds in Florida's coastal waterways, and monk parakeets native to South America hang out in a Brooklyn cemetery. Honeybees are dying off in droves, but President Obama is taking them in and taking up their cause. Donkeys worked as pack animals in the gold mines of the Wild West, but these days they're ruling the streets of an Arizona town.