We have a 5 month old collie pup who generaly seems to be well adjusted and happy. At night she sleeps in a crate in the garage and is fine with that. My problem is that during the day, when she is obviously exhausted,  say after a walk or when she just needs a nap, she cannot settle anywhere but closed in her crate, in the garage. If I leave the door open on her crate so that she can sleep in there without being "closed in " she just wanders about.
I don t want to have to lock her in for a nap but this seems to be the only way she can get any rest.  In the house she has a basket with cushion-which she never goes in and a mat which she just chews!- Any suggestions?

Only a guess but can you not bring the crate in the house?

maybe she just likes the secureness of her crate its her little safe haven. try bringing it into the house as natalie suggested and dont think of it as locking her in, its what she wants :)

Could you cover the crate when it's in the house?  Maybe there is just too much stimulation in the house?

Over stimulated collies is a subject I've been discussing recently - so many collie owners have read that they need to be stimulated, because they are bred to do a job, but they fail to teach the dog to settle, and forget that a working dog will actually only work 3 days a week, and then only in short bursts.  Too many 'family pets' are provided with activities all their owners waking hours, and they never learn how to 'chill' :(