The work of Clark et al. in this issue of J. Neurophysiology extends the analysis of thermotaxis in C. elegans by providing a detailed analysis of the adaptation of thermotactic behavior. Previous work indicates that thermotaxis in C. elegans involves a biased random walk in which changes in temperature alter the duration of the runs that an animal makes between turns. Interestingly, the authors find that although behavioral responses to increases and decreases in temperature have opposite effects on run length, the two responses are of similar magnitude and adapt with similar kinetics. These properties are predicted to allow the system act as a band-pass filter that would be less sensitive to temperature fluctuations occurring on a time-scale significantly faster or slower than the time needed for an average run. This analysis of C. elegans thermotaxis raises potential parallels to bacterial chemotaxis, with the kinetics of adaptation playing an important role in determining the ability of the organism to sense a stimulus gradient. This raises the possibility that diverse organisms may exploit similar system properties to solve similar problems, such as the problem of responding robustly to subtle gradations in an external stimulus.