This is due to a variety of factors, including its smell[10] and the stains it leaves on the walls.[10][11][12][13] While that stain makes it easier to check whether the room has been sprayed, it causes some villagers to resist the spraying of their homes[13][14][15] or to resurface the wall, which eliminates the residual insecticidal effect.[12][15] Pyrethroid insecticides are reportedly more acceptable since they do not leave visible residues on the walls.[13]