I personally feel having pets around is a very nice thing. Specially while in a small family or when someone is living all alone away from their family, pets can fill in the gap. Though they cannot speak like we do but they do have various ways of expressing their feelings towards us. When you come home after a long day's work they would show how happy they are to see you by jumping on you. They would show they are hurt when they whimper in pain or they are angry when they growl.
They can be our friend in need and also protect us while we are in danger. Though sometimes we might underestimate an animal but they are very very sensitive to their owners physical and mental state. They very well understand when their owner is sad, or upset or worried. As they cannot speak they wont verbally empathize with us but they would surely show us how much they love us by sitting next to us or licking us. Pets can complete a family and also be wonderful friends for life.