Answer:
I come in different colors and shapes. Some parts of me are curvy some are straight. You can put me anywhere you like but there is only one right place for me.
An action done on mosquito bites
I travel in a gaggle.
I do not contain flesh feather or scales; yet I have fingers and thumbs.
Always in you, sometimes on you. If I surround you, I can kill you. What am I?
The warmer I am the fresher I am.