Color and cut out the monkeys.
Glue each monkey to green construction paper. Trim the green paper to measure about 6 inches by 7 inches. Cut card stock (or cereal box cardboard) into 2 6-inch by 7-inch squares.
Glue each of the monkeys on green paper to a separate square of card stock. Place the straw between the two pieces of card stock. Put one staple through the paper, straw, and cardboard, then staple around the edges of the whole square.
Hold the straw between the palms of your hands, with the monkey sticking out above. Roll the straw back and forth through your palms so that the monkey pictures flip back and forth. If you do it fast enough, it will look like the monkey is brachiating (swinging by its arms).