This is the starting point of standard intonation. I'd better stress every word. Well, not quite. In standard English, we consider that the nouns carry the weight of a sentence, when all else is equal. Although the verb carries important information, it does not receive the primary stress of a first-time noun.
Dogs eat bones.
After the information has been introduced, or is being repeated through the use of pronouns, the intonation shifts over to the verb. They eat them. This has to do with your natural understanding of phrasing. In a sentence, phrasing tells you where the speaker is at the moment, where he is going, and if he is finished or not. Notice that the intonation stays on the nouns.