Enginge chattering or ticking helppp!!!

so i woke up this morning and started my car and i start hearing this ticking chattering sound i will include a video so you can hear for yourself , please what is this noise and can it be harmful to my engine?
http://www.youtube.com/watch?v=DC-ufkAvV0o
http://www.youtube.com/watch?v=DC-ufkAvV0o