What's going on with `method_missing` and `puts`?

Question

I printed a collection of objects that implemented the method_missing method. The following example demonstrates this:

class Foo
  def method_missing(m, *args, &block)
    puts "missing method in #{self.class} #{m}"
    super
  end
end

bar = [Foo.new, Foo.new, Foo.new]

bar.each { |i| puts "#{i}" }
puts "====================="
bar.each { |i| puts i }
puts "====================="
Foo.new.to_ary 

Output

#<Foo:0x00000000d62ba8>
#<Foo:0x00000000d62b80>
#<Foo:0x00000000d62b58>
=====================
missing method in Foo to_ary
#<Foo:0x00000000d62ba8>
missing method in Foo to_ary
#<Foo:0x00000000d62b80>
missing method in Foo to_ary
#<Foo:0x00000000d62b58>
=====================
missing method in Foo to_ary
./missing_test.rb:6:in `method_missing': undefined method `to_ary' for #<Foo:0x00000000d61e60> (NoMethodError)
    from ./missing_test.rb:16:in `<main>'

1. Why is to_ary called? (I think it has something to do with the way puts tries to dig down and provide some info recursively.)
2. Why does the call to to_ary (generated as a result of puts) not generate a missing_method error? It is not supported by Foo (or Object). All my method_missing method does is print the method name and then call super, so if to_ary shows up as missing, the call to super should throw a method_missing exception, right?