Assign one person as the cat and another person as a mouse. Have the rest of the class line up in equal rows and lines forming a 5x5 or 4x5 grid. Call out "streets" and the students forming rows hold hands and connect. Call out "alleys" and the individuals forming columns connect and hold hands. As these commands are being called out, the cat is trying to chase the mouse while the streets are changing to alleys and alleys are changing to streets.