Dog eats everything outside
My female pom mix is 2 years old, I adopted her 2 months ago. I feed her iams dog food. We live in an apartment. My problem is every time I take her out for her walk, she acts like she has to find something to eat and most of the time she does, like dead birds, bark, rocks, paper anything. She keeps her nose to the ground and picks up anything and tries to eat it. She doesn't do this in the apartment; only when I take her for her walks 3 to 4 times a day. Do I need to change her diet, or is this a bad habit and if it is, how do I correct it.