Blue (my 1 year old min pin) was crate trained before I ever adopted her and she used to go into her crate fine initially. She even slept through most of the night going to bed at 10pm and waking up at 7am. Lately, she's been going to bed around that time (walking into her crate voluntarily) but waking up at around 2am. Of course for working souls like myself this is hard to deal with because she'll start barking and doing the most heartbreaking crying.

I usually keep her in the crate until I can drop her off at my parent's house before work where she has a huge backyard, house, and people to keep her company until I pick her up to go home again at around 2:30pm. The only time she's really alone is during the night when everyone is supposed to be sleeping.
I'm not sure how this problem developed, it could have been due to my varying schedule breaking routine. At first I thought it was because she needed to use the bathroom but that isn't the case most of the time. I tried letting her out one time at 2am and all she did was run to chew on an old sock until she got tired and went to sleep on my bed. Now when she's at my parent's house she'll act nervous/pace until I come to pick her up again.
What can I do about this?
Take her to the vet and rule out an underlying medical problem. I think I remember reading about some problem being related to fear of the dark, but I am not sure.

Melanie Lee Chang > Form ever follows function. Departments of Anthropology and Biology >
University of Pennsylvania > Louis Sullivan (Email Removed) >
What can I do about this?

If you can brave a few more sleepless nights try training her to play independently if she wakes up in the night.
I did this with great success (so far & touching wood!!!) with my weim pup ~ basically, every time she fussed I pointed out & played with the toy & chew left for her (not nec. so easy, a lot of ignoring, back turning and patience involved!!) ~ now she'll play happily, ok if not a little noisily ~ but I'd rather be woken up by a noise telling me all is OK than one that wants me to get out of bed!
Good luck, I sleep well now :-)
Diana