perching at night

My 3 new ladies are showing no signs at all of wanting to perch on the the roosting bar when they go to bed.    They are older birds and im sure that were they came from they werent provided with roosting bars.   Question,  is it law that chickens have to perch at night, if they choose to sleep on the floor can you just leave them to do that.         Nickyx

Hi Nicky
None of mine perch.  I put the perch in position the other day and we had added an extra rung for them to climb up and I found it had pulled up so they couldn't perch - mine are very high perches.  One had obviously tried getting up.  I will have to put a piece of wood above the perches so that they slot in and that way it will stay put.  All of mine used to huddle up in one or two nest boxes and now with the warmer weather they sleep in the house and only one sleeps in the nest box. 

Mine never perch even after weeks of training as soon as i leave them they are back in the nesting box. Idealy they should be on a perch because if they are in the nesting box they get the eggs dirty but i am always up early before any eggs are layed