Adult Oryzaephillls surinamensis (L.) showed a strong hygronegative response to a choice between relative humidity alternatives of 60 and 100% and a moderate hygropositive response to a choice between 10 and 50%, but they were indifferent, or nearly so, to alternatives of 0 and 40% RH . In uniform humidities they showed a strong photonegative response and a strong preference for a high level of contact stimulation. When the photonegative and hygronegative responses were opposed, they canceled one another. When the tactile and hygronegative responses were opposed, the hygronegative response was suppressed and the tactile response was weakened. The light and tactile responses both suppressed the hygropositive response without being weakened. When 2 responses (light and humidity or tactile and humidity) operated in the same direction, the resulting compound response was typically no stronger than the strongest of its components. The light and tactile responses were not influenced by humidity alternatives of 0 and 40% RH .