When I take Smokey out for a walk in the park on the path, I practice getting her to come to me and sit and sometimes I give her a treat when she does it. For the most part, she does this with no problem. Sometimes,however, she ignores me when I call her. This usually happens when she is looking around at the scenery and apparently has found something interesting to look at or smell. I then have to call her repeatedly for 30 seconds or so until she finally reluctanly turns and comes to me. It's like she puts me on ignore until she is ready. Now is this normal for a dog to do this sometimes, and if not, is there a way I can get her to react everytime I call her?