Really depends on the snake. I only have 5 BPs and there is variety in that group. 3 of them will get on my hands and arm when i reach for them and will chill and explore calmly, 1 will tolerate me handling but will try to "run away" sometimes. And 1 doesn't like handling. She will just ball up and not move. After maybe 10 minutes she will begin to explore a little but she moves fast trying tto get away. There is no way to tell for sure if they like it but over time you are able to read their body language and behavior so you can make an educated guess. For me the main thing was just time. There is no substitute for experience.