My dad bought him these little rubber ducks when he was about 6 mths old, and I am sure glad I brought them over to cambridge, they are his truest companion at bath time! I would ask him to look for the duckies, he would do so, then he would have his duckies in his hands the whole time he is in the bath and sometimes, even after towel dry and change, he would still be holding them tightly in his small little hands.
He particularly likes banging them together to make the 'squeaky' noise.