When all the animals were on Noah's ark, he addressed them and said "Now, we're going to be here for a while, and there's only so much food and room, so we all need to hold off on the 'be fruitful and multiply' thing, okay?" And all the animals nodded.
After forty days and nights, the ark grounded on the mountain, and all the animals started to file off two by two... except the housecats. Mama cat, six kittens, tomcat.
The tomcat looked at Noah and grinned and said "YOU thought we were fighting, didn't ya??"