Which uncontrollable variable in his first experiment did Von Frisch correct in the second experiment and why was it important?

In his first experiment, Von Frisch did not account for the variable of light intensity, which could affect bee behavior. In his second experiment, he controlled for light conditions by using consistent lighting to ensure that the bees' responses were solely due to the cues being tested, rather than variations in light. This correction was crucial because it allowed for more reliable conclusions about how bees communicate the location of food sources through their waggle dance, thus enhancing the validity of his findings.