Emperor penguins can grow to four feet or more in height. They are curious and often act like teenagers. Their only natural enimies are seals and orca whales. They have no fear of man. Their curiosity leads them to inspect all the ground equipment, aircraft, buildings and streets at McMurdo Scientific Station. There are thousands of penguins in the McMurdo Sound area and they are active during the summer. The vehicle is a Snowcat, developed by the US Navy to traverse the ice and snow surface. It is all weather and is used for rescue and emergency missions.