Ants use taste to sense chemicals in food and choose what to eat. When offered five bread squares — each carrying a different flavor, including sweet and sour options — ants crowd around the sweet bread and nearly ignore the rest. A plain water square serves as the control and is almost never visited. You count the ants on each square every two hours over five days, and the pattern is clear: taste drives which food they choose.

Animals can sense chemicals from predators, which might be expected to trigger fear or avoidance. Mice are natural prey for cats, so you might expect them to freeze or panic at even a faint whiff of cat scent. To test this, you train 10 mice to run a cardboard maze over nine days. On the tenth day, you place a cloth soaked in cat urine near the end of the maze and time each mouse. Compared to the day before, the cat scent had almost no effect on how fast the mice finished.

Mice are known for their strong sense of smell, and this project tests whether they rely more on smell or sight to navigate. You build a cardboard maze and train 10 mice to find a sunflower seed at the end. After nine days of practice, you cover the maze to block all light, then time each mouse in darkness. The mice solved the dark maze just as quickly as the lit one — suggesting they depend more on smell than sight to find food.