We have a 3.5mo puppy. He's in a great routine and happily goes into his crate at 10pm when we go to bed and sleeps til 6/7am.
Tonight, he just won't settle. Keeps crying 
He doesn't need the toilet and isn't hungry or thirsty.
Could he be teething? Any other suggestions on how to help him? Our last dog was an older rescue so we're novices with a puppy.
It's like having a baby again!