No, not those balls, you pervert. I can't believe that would even cross your mind.
Moving on, dogs love to chew tennis balls. The frequency and the intensity varies greatly from dog to dog, but it's disturbing that they chew on them at all. Humans would never chew on tennis balls, and here's why:
1.) We know they're meant to be thrown. Or hit by a Williams sister.
2.) They taste awful. Trust me, I've tried...I mean, uh, I mean I bet they taste awful. I wouldn't know. I've never ever tried to chew on one. Never.
3.) They've been all over the ground, and so they're covered in dirt, crap, and insect blood.
4.) We would look ridiculous with a tennis ball lodged between our jaws.
And 5.) We would much rather chew our rubber in gum form. A far more dignified way to chew rubber, indeed.
(flickr photo Samson, My Hero by neon.love; http://www.flickr.com/photos/stellarsky/346785492/)