Construct a Python program that takes a list of words and prints the 3rd most common word in the list?
words = ['Cat', 'Dog', 'Bird', 'Horse', 'Cow', 'Lion']
import collections
def third_most_common(words):
    count = collections.Counter(words).most_common()
    return count[2][0]
third_most_common(words) # returns 'Bird'