Zombie ants clamp on to aerial vegetation and hang for months spewing the spores of their parasitic fungi, but researchers noticed that they do not always clamp on to the same part of the plant. Now the researchers know that the choice of leaves or twigs is related to climate and that climate change forced the fungi to adapt to local conditions.

Carpenter ants infected with a specialized parasitic fungus are not subjected to aggression or isolation from their nest mates, and they continue to share in the colony's food resources until they leave the nest for the last time to die, according to a study led by Penn State researchers.

A process using human stem cells can generate the cells that cover the external surface of a human heart — epicardium cells — according to a multidisciplinary team of researchers.

A theory that uses the mathematics of a drunken walk describes ecological invasions better than waves, according to Tim Reluga, associate professor of mathematics and biology, Penn State.

Whether a wild cottonmouth snake will attempt to strike in an encounter depends on its baseline stress level, according to a team of scientists led by undergraduate researcher Mark Herr.

Coral genotypes can survive for thousands of years, possibly making them the longest-lived animals in the world, according to researchers at Penn State, the National Marine Fisheries Service and Dial Cordy & Associates.

Outside of human influences, why do rare plant species persist instead of dwindling away to extinction? It's a question that has plagued ecologists for centuries. Now, for the first time, scientists at Penn State and Universidad Nacional del Comahue, Argentina, demonstrate that fruit-eating birds play an important role in maintaining rare plant species.

Sneaky parasitic weeds may be able to steal genes from the plants they are attacking and then use those genes against the host plant, according to a team of scientists.