Bites

I bought foam swords for the boys earlier this year.  I decided to buy them after I took away the boys' plastic baseball bats, flags (on long wooden sticks), and even butterfly nets after they were all used to beat each other one time too often.  I figured they could hit each other and there would be less blood.  It has been successful so far, but there has been one unexpected consequence:

Can you tell which one is Justin's?