Can tarantulas choose whether or not to use venom in a bite?

[Mudring76]

Don't know how true it is but I've heard that they can do a dry bite. One with no venom depending on the situation or how threatened they feel. Can't confirm it been collecting since 1990 never got bitten hope I never do!

 

[Josh]

I imagine it's something that can happen under the right circumstances. I would not call it predictable in any sense of the word

 

[m0lsx]

Yes, tarantulas can dry bite. That is bite without envenomation, although, I am not aware of any academic papers to support that.