Is This Normal? Prawn eating my snail? Video

[WarrendaFish]

My freshwater prawn is either eating or cleaning my blue snails's shell. I have 2 of each in the tank and havent had a problem thus far.

http://www.youtube.com/watch?v=tKCYL7fkiqM
http://www.youtube.com/watch?v=eRMy9FgFw5o

Is he damaging or aiding my snail?
I can move either to a different tank if it's a problem.

 

[black&white]

looks like cleaning? but dont hold me to that sorry

 

[Camshaft Ramrod]

yup, cleaning.

 

[Psyche]

I see my shrimp pick over snails shells and even the bodies of larger snails. never seems to do any harm.