You can regognize a little sister by the following:
-a sound, normaly called a voice in humans, that penetrates the scull and can lead to severe headaches
-Extremely two faced
-Generally less fun to be with than a pile of s**t on a hot day.
There are ways to escape her.
1. Leave home (recomended)
2. Kill her (Highly recomended)
3. Sitting down and talking out your problems with her (not recomended, may lead to severe injuries)
In all contact with these individuals is better avoided.
Important!! You are immune to other people's little sisters, you can talk to these individuals without running the risk of injury. However, friends of your little sister can have the same effect on you as your sister, but this is not the rule. There have been many examples of guys ending up together with friends of a little sister, but this too is not recomended.