To schatchen means to move something back and forth quickly with your hand or fingers.
Schatchen can be a quick and nervous movement, like when you're excited or anxious.
Examples:
I like to schatchen my dog's ears.
She schatchens her head when she's thinking.
The baby schatchens the toy back and forth.
He schatchens the pencil while he thinks.
The cat schatchens the ball all around the room.
I schatchen the keys in my hand when I'm waiting.