title: Can't access object property of a Mongoose response
body: <p>I'm running this code on node.js</p>
  
  <pre><code>var mongoose = require('mongoose');
  mongoose.model('participant',new mongoose.Schema({},{ collection : 'forumParticipant' }));
  var Participant = mongoose.model('participant');
  mongoose.connect('******');
  
  Participant.find({entity_id: 0}, function (err, docs) {
     console.log(docs[0]);
     console.log(docs[0].entity_id)
  });
  </code></pre>
  
  <p>1) The first console.log return the full document</p>
  
  <p>2) The second console.log return undefinied</p>
  
  <p>I don't understand why.</p>
  
  <p>I need to perform something like</p>
  
  <pre><code>var participants = docs.map(function(d){return d.user_id})
  </code></pre>
  
  <p>How can I achieve that? What am I missing ?</p>