Parameters for :after_create?

Hi,

Does anyone know how to pass parameters to methods called by :after_create?

For instance:

Class Dad < ActiveRecord::Base
  has_many :children

  after_create :create_child(dad)

  def create_child(father)
    kid = Child.new(:name => :bart)
    kid.dad = father
    kid.save
  end

end

Thanks!