The objective of this study was to document the vertical avoidance behavior of the tadpole madtom, as a surrogate to the northern madtom, in response to granular Bayluscide® when applied to control or assess larval sea lamprey populations. The data set consists of one hour recordings of the avoidance behavior of tadpole madtoms after exposure to granular Bayluscide. Each trial (replicated 15 times) consisted of three treated (Bayluscide granules) and three control (washed sand only) clear Plexiglas vertical columns (107 cm in height, 30.5 cm in diameter) with a single madtom per column. Video recordings were analyzed for vertical avoidance at 30 second intervals after addition of Bayluscide granules/washed sand over a period of one hour. Vertical migration of the normally bottom dwelling madtoms to greater than 15 centimeters off the bottom of the column was considered avoidance.