I can't believe I have to say this - Do NOT injure a live mouse to make it "bleed a little". An injured/frightened rodent is much more dangerous to your snake.
Striking and "missing" usually indicates that the BP is being defensive, not trying to eat. Can you upload a pic or describe your setup (tank size, hides, temps, etc.)? How long have you had him and how often are you offering food?
Edit: I see you've only had him since the 8th, so disregard that particular question, and welcome to the site.![]()