define_method doesn't receive block as a parameter ruby

I'm currently doing second week assignment 1 from this metaprogramming tutorial and have some problems with sending block for using it with define_method. The program simply doesn't see the block, returning false when I call block_given? even though I provide a block.

Here's the file that sends the block:

require_relative 'dog'

lassie, fido, stimpy = %w[Lassie Fido Stimpy].collect{|name| Dog.new(name)}
lassie.can :dance, :poo, :laugh
fido.can :poo
stimpy.can :dance

stimpy.can(:cry){"#{name} cried AHHHH"} # the block that I can't receive

puts lassie.name

p lassie.dance
p lassie.poo
p lassie.laugh
puts
p fido.dance
p fido.poo
p fido.laugh
puts
p stimpy.dance
p stimpy.poo
p stimpy.laugh
p stimpy.cry # method call

And the file that receives:

Dog = Class.new do
    MESSAGES = { dance: "is dancing", poo: "is a smelly doggy!", laugh: "finds this hilarious" }

    define_method :initialize do |name|
    instance_variable_set(:@name, name)
    end

    define_method :name do
    instance_variable_get :@name
    end

    define_method :can do |*args, &block|
    puts block_given? # false 
    if block_given?
        define_method args.to_sym do
        yield
        end
    else
        args.each do |ability|
        self.class.instance_eval do
            define_method "#{ability}".to_sym do
            @name + " " + MESSAGES[ability]
            end
        end
        end
    end
    end

    define_method :method_missing do |arg|
    puts "#{@name} doesn't understand #{arg}"
    end
end