Why Does My Sweet Boy Go Into Striking Mode Only At Night When Someone Comes Upstairs

[Seviper]

Before I begin, he's kept outside all of the bedrooms upstairs on top of a large drawer.

Anyway, even if he's just eaten, if someone comes up the stairs, he'll be in the S-position moving towards whoever's walking past. He doesn't *always* do it, and when he's calmed down a bit I can get him out. If he's not completely calmed down, I can gently touch his neck, lift up his hide and then get him out and he's back to being sweet as hell. Never happens in the morning, only from 7PM onwards and he stops doing it after 10PM. I do know I'll get bit if I stick my hand in there, because it's happened once but he let go instantly then he was back to being really sweet. Also, if I just stay in my room and come out at any time he will never do it... ever. Only if someone comes up the stairs.

I know he isn't stressed, because he gets to be completely alone all day every day in silence to sleep because everyone is either at work or downstairs. His temps are fine, 78F on the cool and 90F on the hot, and the humidity of course is 55% on the hot side and 60% on the cool.

I asked my breeder about this, and he said he's just in feeding mode but I find it VERY odd that he's so eager to go after me even though I smell nothing like a mouse and I obviously don't have any mouse smell on me. Is this even true? I mean, he's an outstanding feeder and never refuses meals outside of being in shed. He's amazing at being handled and even goes up to my face all the time, lays on top of me while I watch TV, snuggles against my arm and hand..... I know he's not an aggressive BP and I know he is happy and well fed. So, why is he doing this S'ing thing? Is it really due to a feeding response and he doesn't think that it's just his owner walking past?

EDIT :: Forgot to mention, literally the moment I touch him, he snaps out of it and everything is hunky dory.