A field of grey, motionless kangaroos staring down a bicyclist in a recent YouTube video is not evidence of marsupial zombies, scientists say — though the pouched Australians look eerily possessed.

The upright kangaroos peer intensely at Ben Vezina, who posted the video on YouTube on Aug. 23, as he approaches them on bike in Hawkstowe Park in Melbourne. When he gets close, the stoic-looking animals bounce away.

Although the zombielike kangaroos look ready to devour Vezina, their behavior is much more benign and typical. "It looks really normal," said Marian Powers, a zookeeper at Fort Wayne Children's Zoo in Fort Wayne, Indiana.

"Kangaroos are really curious and inquisitive animals," and are very aware of anything that is odd to them, Powers told Live Science. The kangaroos in the video were likely interrupted from their grazing when Vezina suddenly appeared, Powers added. [See Photos of Kangaroos and Other Cute Marsupials]

Vezina was in no danger of being attacked, Powers said, although male kangaroos can be aggressive during the breeding season. Typically, the kangaroos are docile and timid.

Their rapid leaps away from Vezina are also typical of kangaroos, Powers said. The mammals scatter when they're startled, moving as fast as 30 mph (48 km/h).

The kangaroos in the video are very likely eastern grey kangaroos (Macropus giganteus), Powers said, which can grow to be 5 to 7 feet (1.5 to 2.1 meters) tall. These kangaroos can weigh up to 200 lbs. (90 kilograms), and live for around 10 years in the wild and 20 years or more in captivity, according to Fort Wayne Children's Zoo’s website.

Fort Wayne Children's Zoo hosts the largest North American population of eastern grey kangaroos, although in the wild, the animals live in Tasmania and eastern Australia.

Eastern grey kangaroos prefer the heavy scrubs and forests of coastal and mountainous regions, but they also dwell in grasslands and open woodlands, according to the zoo.

These kangaroos live in groups with one large, older male, two to three females with joeys (baby kangaroos) and two to three younger males. The joeys, which start their lives the size of jelly beans, leave their mothers' pouches after 11 months.

Groups of the animals graze together on grasslands — the kangaroos Vezina peddled toward in the video were likely doing the same.

Elizabeth Goldbaum is on Twitter. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science