Boa has been extra pissy for 2 days?

In his 2.5 years, he has never struck me or acted this way. Nothing has changed regarding his temperature, humidity, amount of hides, and he’s not hungry. He has plenty of enrichment and is always extremely docile. This behavior I will explain below is very unusual for him. He just had a rat (the same size as always) 2 days ago. He is not showing any symptoms of being ill but I know well with reptiles that can be sometimes slow to show.

For the last 2 days, anytime I’ve walked past his tank he gets into a stance as if he will strike and sometimes he even does, hitting the glass.

Before I make this 3 hour long drive to take him to the exotic vet, I just wanted to see if anyone else has ever had this issue. Like, is it possible for snakes to have “bad days”? I’ve never experienced this behavior from any of my reptiles and I am a bit concerned