I have a smaller backyard city set up and have 6 girls in there for about 2 weeks now. my question is, how do i get them to use the ramp to get in and out of the coop? we put them in there at nite and close the door to the outside. in the morning i go out and open the door and they go running out. but at nite i have to physically grab each one and put her up top, they wont go up the ramp into the coop! do i have to train them to do this....and how? they are about 9 weeks old, and i took away the heat and food in the coop now....we get nite time temps around 30 now.