Earlier studies have shown that some of the compounds cause hyperactivity and thinking deficits in laboratory animals.

VOA: special.2010.05.26

Some people say it represents invasion of the animals' territory for no good reason.

VOA: special.2009.06.16

But some of them now defend the animals and work to keep them alive.

VOA: special.2009.05.05

For hunters,these five animals were some of the most difficult and dangerous to catch.

VOA: special.2009.08.19

It might surprise you that there are too many of some other animals.

VOA: special.2009.08.19

Some of the chemicals are harmful to both humans and animals.

VOA: special.2009.09.22

Some of the animals live nowhere else on Earth.

VOA: special.2009.12.16

Bigger livestock herds are putting greater pressure on land resources and disrupting some ecosystems and the animals generate significant amounts of water and air pollution, including methane, a climate-changing greenhouse gas.

VOA: standard.2010.02.22