Why Did my Boa Change his eating Habits?

I have a 13 month old male colombian red tail boa, just over 4 feet. I just moved across Canada about 2 months ago with him. When I first arrived he didn't eat for a couple weeks, which I expected. Then he had 2 meals (frozen thawed rats) with no problems but then when the third meal came he didn't want to eat. I kept trying but he just wasn't interested, so finally I went out and bought a live rat and he ate that. Last night was his feeding day and I put a frozen thawed rat infront of him, wiggled it around and he seemed interested but when he got close he back away and didn't want it. So, i finally decided to place the thawed rat in one of his hides and went to bed. When I woke up the rat was gone, so he had eaten it. Now why all of a sudden is he eating so strange? He has never had any problems eating and was always ready for food and would take it from my hand with no problems, then suddenly after I move he won't take the food from me. I have to place it down in the cage and walk away. Why has his feeding habits changed?