How does telotaxis differ from tropotaxis when an animal faces two light sources?

When an animal encounters two light sources, the difference between tropotaxis and telotaxis lies in how the organism processes the competing stimuli to achieve orientation.1

• Tropotaxis: The animal makes a simultaneous, automatic comparison of light intensities on both sides of its body using paired receptors. When faced with two light sources, the animal orients itself toward an intermediate point between them, effectively balancing the stimulation so that both sides of the body receive equal intensity.12
• Telotaxis: The animal treats a light source as a specific goal. Rather than balancing the two sources at an intermediate angle, the animal orients directly toward one light source at a time. It may switch its orientation between the two sources at unpredictable intervals, resulting in a characteristic zigzag path.1

Unlike tropotaxis, which relies on bilateral balance, telotaxis does not require the animal to maintain equal stimulation across its body.1