Ok what sounds better?

1. when the herd does notice that a pride of lions are preying on their young the hippos will often form a defense circle with their young in the middle and with the toughest hippos on the outside in order to protect their young.

2.when the herd does notice that a pride of lions is preying on their young the hippos will often form a defense circle with their young in the middle and with the toughest hippos on the outside in order to protect their young.