U.S. bats in deep peril

Brown bats, like this one, contribute an estimated $23 billion annually to the agricultural industry through insect control and pollination. But that's money farmers might have to spend on pesticides as more and more bats die.

U.S. Department of Fish and Wildlife officials say bats are dying of a fungus ailment called White-Nose Syndrome. The fungus first showed up five years ago in a cave near Albany, N.Y. It's believed the crisis began when hikers unknowingly brought the fungus into the cave on their gear.

Dying bats called No. 1 mammal crisis in U.S.

The U.S. Department of Fish and Wildlife has declared bats the No. 1 mammal in crisis in the country. White-Nose Syndrome leaves a fungus on a bat's nose, wings and body that eventually leads to starvation.

An albino little northern free-tail micro-bat sits on person's thumb in Kuranda, Australia.

Dying bats called No. 1 mammal crisis in U.S.

White-Nose Syndrome, CBS News Correspondent Betty Nguyen reported on "The Early Show," has wiped out a million bats in 18 East Coast states in the U.S.

Several bats are seen here hanging together upside down.

Dying bats called No. 1 mammal crisis in U.S.

A bat is tagged with a transmitter in research efforts to find out why the widespread bat die-out is happening. A cure for White-Nose Syndrome is currently unavailable.

On "The Early Show," CBS News Correspondent Betty Nguyen noted one of the consequences of the bats' deaths is more bugs. Farmers depend on the bats to kill bugs that feed on their crops. Bats contribute an estimated $23 billion annually to the agricultural industry through insect control and pollination. That's money farmers might have to spend on pesticides.

Dying bats called No. 1 mammal crisis in U.S.

The U.S. Department of Fish and Wildlife has declared bats the No. 1 mammal in crisis in the country.

A bat is examined by a researcher with the U.S. Fish and Wildlife Service.

Dying bats called No. 1 mammal crisis in U.S.

Researchers tag some bats' backs with transmitters and release them back into the wild. Researchers hope the information the bats give them will lead to more answers.

A bat caught for research by the U.S. Fish and Wildlife Service.

Dying bats called No. 1 mammal crisis in U.S.

A farmer interviewed by CBS News said the effect on farmers if this fungus illness spreads to more bats across the U.S. could be catastrophic.

James Roby told Correspondent Betty Nguyen, "It could be apocalyptic, because we're talking about a check that's been in place for years that takes hundreds of tons of insects out of the ecosystem. And that problem is going to be very similar to the clouds of locusts. Not only is it going to affect our crops, but it's going to affect our people."

An adult female Gould's Wattle bat in Sydney, Australia.

Dying bats called No. 1 mammal crisis in U.S.

The only thing officials can do now to fight White-Nose Syndrome among bats in the U.S. is to close off certain caves and mines where the bats go to hibernate, and research how to stem the die-off.

An Australian East Coast freetail micro bat eating a a worm in Sydney, Australia.

Dying bats called No. 1 mammal crisis in U.S.

Farmers in the U.S. count on bats to eat 100,000 tons of crop-damaging bugs every year. CBS News correspondent Betty Nguyen reported bats contribute an estimated $23 billion annually to the agricultural industry through insect control and pollination. That's money farmers might have to spend on pesticides.

A flying fox bat soars above trees at Royal Botanic Gardens in Sydney, Australia.

Keep clicking through the slideshow to see more bats from around the world.

Dying bats called No. 1 mammal crisis in U.S.

An adult female Gould's Wattle Bat in Sydney, Australia.

Dying bats called No. 1 mammal crisis in U.S.

A baby white-winged vampire bat.

Dying bats called No. 1 mammal crisis in U.S.

A fruit bat hangs from gloved hand.

Dying bats called No. 1 mammal crisis in U.S.

A fruit bat.

Dying bats called No. 1 mammal crisis in U.S.

A baby fruit bat feeds on milk.

Dying bats called No. 1 mammal crisis in U.S.