Since last saturday I have collected 1 egg a day. But so far I haven't heard any "singing" when the egg is laid. Today I actually spent alot of time in the kitchen and back yard so that I would hear it. I went out at several times between 8 am and 10 am and no egg. When I went out at about 10:30 there it was right in the nest box and I never heard the song. Is this normal?