Why did a toy only bite B.A.P Youngjae?

This was from Heyo TV B.A.P private life 170915 I changed the arrangement of the video in order to make it more fun lol sorry for that B.A.P's reactions are so precious when Youngjae got bitten lol Also I'm sorry I only know Korean a little so I explained the situation instead I hope you're enjoy it and please support B.A.P ^^