There may be an innovation arms race between humans and trash cans. Humans try new defenses, such as putting bricks or rubber snakes on the bin lid, but the birds are still able to open them.

BRAZIL

The oldest known mammal is Brasilodon, an animal that lived more than two centuries ago. Scant fossil evidence made the animal hard to classify, but new analysis shows it's a mammal.

DENMARK

It is the first United Nations member state to pay for the damage caused by its greenhouse gas emissions. The countries hit hardest by climate change will benefit from the donation.

GERMANY

The world's first hydrogen-powered commuter train route is in the works. The trains offer a green alternative to diesel fuel.

INDONESIA

A child on the island of Borneo had the lower part of his leg removed. There are signs that the child survived the procedure.

PANAMA

Some tree species are killed more often by lightning than others, according to a study along the Panama Canal. Palm trees almost always die when struck by lightning due to their lack of dense wood and large water carrying tissues.