What are these and where do they go?

[truckin 79]

I took out front grill to put in a new one and before I could get the new grill in I had to go pick up wife with a flat tire on her bike. I drove down the road hear some rattling and then I hear something hit the road and I run one of these things over. Now I am not sure if I need these things or not, I am sure they go somewhere in the front but just not sure where.