hi ive got 2 rir in point of lay that i got over a week ago,and ive got the chicken bugg so i want to expand my flock..im currently building a coop 6ft x 5ft by 6ft high..i would like to buy some fertile eggs and an incubater off the net.and.i would like to know ,will my new hens after hatching need to have been mated with a roo{ just once }for them to start laying or do they just lay eggs? also i would eventually like 6 chickens in total is 6x5ft run with a raised house large enough..thank yu