Some people say it makes no difference some say it's helps,I like it, so if you have a light in the loft on a timer have it set to come on about 4 am.( it wants to be on anytime now ) this will fool the pigeons into thinking that spring is on its way and you can guess what happens next.Hopper feed, then when the eggs have hatched there's feed in front of the birds when the light comes on.If you can't hopper feed make sure the pots are full when you lock up.Plenty oyster shell grit,even crushed egg shells and plenty of pick stone.If you have any nervous birds don't bother them too much once the eggs get chilled,they might not hatch.
Lindsay.
JMO.