the longer you keep them in dave, the stronger on the wing they,ll be,, i would let them out asap,, providing, theve eaten in the loft for a couple of evenings , they will soon go back to where they got their last feed,,[better if they can see out from within the loft via cage or sputnick,in this couple of days],,, let them out peckish,,,, with a little seed for them to pick at,, [try and get them as young as poss] even put a bath out for them,, they usually love a bath , once in the bath, they will sit around and see around,, then hopefully they will go back in for their feed ,, good luck, hope all goes well