In this activity, learners sniff out scents hidden in balloons! After investigating, learners discover we sometimes can use another sense (smell) to detect things too small to see. The activity makes connections to the field of nanotechnology through the tiny size of scent molecules, measured in nanometers, or one-billionth of a meter. Step-by-step instructions are included with photos along with safety recommendations. Activity guide includes a "What's going on?" explanation and quick connections to atoms, molecules, and nano-sized sensors.