How long will it take chicks to learn to go up a ramp? My chicks are almost 4 wks and they come out of the brooder down the ramp just fine. But I have to pick up every one each night and put them back in. I have even tried herding them up the ramp, stapled cardboard side boards on, they just fly off after about a foot. When will they "get it"? ramp is a 2ft rise and 6ft length.