We just built a door and ramp to drake house. But I am concerned the ramp is a bit steep and slippery for them to walk up. Especially in freezing weather. We used carpet remnants for ramp of hen house, but am wondering what others have used to make their ramps non-skid. Not sure the non-skip products from hardware store will work that well with ducky feet and this kind of an angle? Had considered nailing/stapling wooden strips to ramp, but not sure how far apart they should be? Any suggestions?