Twitchy (adjective)

1. Easily agitated or excited.
2. Unable to remain still or calm.
3. Nervous or anxious.

Origin:

From twitch + -y, from the verb twitch ("to make a small, sudden movement").

Examples:

1. The horse was twitchy and hard to control.
2. He was feeling twitchy before the big meeting.
3. The twitchy cat kept moving around and couldn't settle down.
4. The twitchy driver kept changing lanes.
5. Her twitchy behavior gave away her nervousness.