I've always been kind of interested in observing people's behavior.

There aren't any around today, so you can't observe their behavior.

Babies observe others' behavior around 9 to 12 months of age.

We're observing behavior that suggests a kid is at risk.

All we can do is observe their behavior and react to it when necessary.

The children who had observed mild behavior reacted in such a way.

Anxiety, though, is fairly easy to measure by observing behavior.

By 2006, researchers had observed consistent migration and other behavior.

It's always difficult to know quite why animals act as they do, especially when it is not often observed behaviour.

It is one thing for an ornithologist to observe such behavior.