The Dink Network

Im making the spike sprite fight for dink. I got it chasing other sprites having brain 9, but it does no damage;
sp_brain(&current_sprite,9);
sp_strength(&current_sprite,7);
sp_nohit(&current_sprite, 0);
sp_distance(&current_sprite, 40);
sp_speed(&current_sprite,1);
sp_touch_damage(&current_sprite,7);
int &mtarget = get_sprite_with_this_brain(9, &current_sprite);
if (&mtarget > 0)
{
sp_target(&current_sprite, &mtarget);
}
// I'm not even sure what sp_nohit does, but it didn't work with or without it. Any clues how to make it damage other sprites? Does it need an attack seq ?