Rubber Duckie, you're the one!

Joshua has one little rubber duckie, and it must be his favorite toy. I can put him down with 15 other little things around him, but if the duck is there, he will find it, and he will not care about anything else! I have tried putting it in the bathtub with him, but there isn't quite enough space for him to really play with it. Maybe his favorite color is yellow; I don't know... I just know that he must have that duckie whenever he sees it! And when I say "must have," I mean:

1. cram it as far into his mouth as possible
2. pull it away to get a quick look at it
3. perhaps rotate it around a little bit to view it from different angles
4. repeat steps 1-3