Who invented the pet door?

The invention of the pet door is often attributed to Sir Isaac newton, who is said to have created a flap-style door for his cat while working at the University of Cambridge in the 17th century. However, there is no definitive evidence to confirm this story. Pet doors have evolved over time, with various designs and improvements made by different inventors. The modern pet door as we know it today has been developed through the contributions of several individuals and companies.