A lot of people know about it, but most does not know. That is why, I want to tell. Such named 'biovampires' steal an energy from the other people. It is dangerous - a human may die. 2 main categories:
1. They want to intenerate a human, to force him open (subconsciously), so that to remove a protection and suck an energy. In a meeting someone may say: - I'm ill. And begin to count the own deseases. You may say: - Don't tell me it. Do not want to hear. Or, you may say: - All of that is a blah. But I'm ill a cancer, siphilis, AIDS, tuberculosis and so on. :-) He will quickly go away.
2. They like to provocate, angry a human, so that he does not control yourself. Usually they go to the public trades (sellers, waiters) or become the little chifs. Like to carp, to lout.
Else, another manner. Someby walks in the markets, other public places with many people and takes an energy from some people a bit by touching.
The beginners do it unconsciously, then, consciously.