How does tropotaxis use paired receptors to orient an animal?

In the context of stereotyped response, tropotaxis is an oriented locomotory reaction that allows an animal to achieve direct orientation toward or away from a stimulus without the need for trial movements or deviations.1

This process relies on the animal possessing paired intensity receptors located on opposite sides of its body. Orientation is achieved through the simultaneous, automatic comparison of stimulus intensities between these two receptors. By turning toward the side that is either more stimulated (for positive responses) or less stimulated (for negative responses), the animal balances the input until both sides are affected with equal strength.12

If an animal is exposed to two sources of stimulation, it will orient toward an intermediate point determined by the relative intensity of those sources. If one of the paired receptors is effectively covered or disabled, the animal loses its ability to maintain this balance and will move in spirals, a behavior known as circus movement. This type of response is commonly observed in many arthropods, particularly insects.1