Cartons with a capped spout — think orange juice, milk, and Boxed Water — can be repurposed as tops for mason jars to give you an accurate pour. To make a mason jar with a capped spout ...
After a while, the animal will lick at the juice spout every time it hears the bell, in anticipation of the juice. If the animal then sees a coloured light (stimulus X) together with the bell ...