This particular article states:
Although many saints are associated with particular animals, Saint Francis of Assisi (1182-1226 C.E.) is most closely associated with the popular trend of animal blessings. During or near October 4th, the feast day of this patron saint of animals and the environment, a significant number of animal blessings take place.
St. Francis developed a profound connection with living things through his fascination with nature. His main inspiration came from animals. He viewed animals as living examples of spiritual integrity, blessing them and striving to understand and connect with them. St. Francis is remembered for his love of all creatures, especially birds, and is probably most known for his "Canticles to the Creatures" and "Sermon to the Birds."
Well, I am somewhat familiar with St. Frank, but I don't think I ever knew any of this stuff. Innaresting. Anyway... we will be observing 'World Communion Sunday' this week.