Fcrate is right about the scorpion venom being...not so bad. An adult shouldn't have too much trouble with it unless it's specially allergic or sensitive to it. But a child is an entire different story. I am also thinking that perhaps the venom sucking has the intention of making the child feel better, seeing that someone is doing something concrete to help them. If in the end it did not help, well, at least the boy felt a little better for a while.
And I immediately understood Otlan reference (of the scorpion and turtle) because when I posted about the cat's nature I was thinking in the same story. The thing is...I don't really like that story. Or to say it better, it is true that animals have some natures that are very difficult to change but I know that story is generally used to talk about human beings. I feel people can change if they really try hard to do it, so the "oh, I can't change, it is in my nature" subtext is just lazyness (or cowardice). I am not saying it from holier than thou point of view, all the contrary. I am also lazy and coward when trying to change and be better, but at least I try to not deceive myself.