Stephane Granzotto / Alpine marmot (Marmota marmota) standing alert outside burrow, takes fright and runs inside, Rhone-Alpes, France, July.

Stephane Granzotto / Alpine marmot (Marmota marmota) emerging from burrow, standing alert and looking around, Rhone-Alpes, France, July.

Stephane Granzotto / Alpine marmot (Marmota marmota) standing on a rock, alert, Rhone-Alpes, France, July.

Eric Baccega / Group of Banded mongoose (Mungos mungo) with two standing on hind legs alert, Masai Mara National reserve, Kenya, Africa.

Ann & Steve Toon / Meerkats (Suricata suricatta) standing alert, Kgalagadi Transfrontier Park, Northern Cape, South Africa, January.

Ann & Steve Toon / Meerkats (Suricata suricatta) standing alert, Kgalagadi Transfrontier Park, Northern Cape, South Africa, January.

Ann & Steve Toon / Meerkats (Suricata suricatta) standing alert, Kgalagadi Transfrontier Park, Northern Cape, South Africa, January.

Tony Heald / Meerkat (Suricata suricatta) two adullts with young emerging at sunrise, Kgalagadi Transfrontier Park, South Africa January

Tony Heald / Meerkat (Suricata suricatta) two adullts with young emerging at sunrise Kgalagadi Transfrontier Park, South Africa January

Tony Heald / Meerkat (Suricata suricatta) two adullts with young emerging at sunrise Kgalagadi Transfrontier Park, South Africa January

LYNN M. STONE / Eastern Gray Squirrel (Sciurus carolinensis) alert by tree, in spring, Geneva, Illinois, USA

Dave Watts / Yellow Mongoose (Cynictis penicillata) standing alert, Kgalagadi National Park, South Africa