When I first got my oldest BP 23 years ago he hissed at me too. Once he was used to getting picked up and handled he stopped. With a little gentle consistent handling they should be more accepting that you are not going to eat them. As long as you are careful to not startle them they should become accustomed to handling fairly quickly.

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1.0 normal BP Nicodemus
1.0 BP Moufasa pos vanilla, fire, cinny
0.4 Cal Kings 3 alb 1 het Dora Queen Ace Pearl
2.0 Alb Corn Bizaar Elixir
0.0.1 Rev Alb Nelsons Oden