Here Viki shows obvious enjoyment over blowing out matches. Notice how she blows them out: she uses a ‘cheek puff’ to extinguish the flame. When you blow out your birthday candles on your cake, you probably will draw a deep breath and then purse your lips to create a constriction. This allows you to sustain a high-velocity airstream for a considerable period of time. Chimpanzees do not appear to have the same ability to control their breathing that we do. Viki generates short puffs by closing her jaws rather than using her lungs and struggles to blow out a match.