Do dogs have a sense of humour?

Cliped from the UK Daily Mail: http://www.dailymail.co.uk/pages/live/articles/technology/technology.html?in_article_id=461113&in_page_id=1965

Do dogs have a sense of humour? (And other questions scientists can't answer)By MICHAEL HANLON - Put yourself in the shoes of our ancestors, 3,000 years ago, and look around you. Raise your eyes towards that big, bright disc in the sky which goes up and down, once a day.
What is it, what causes it to shine? No idea. No idea what goes on inside the body, either.
Our forebears' ignorance was profound. Today, of course, we know what the sun is, and exactly how our bodies work. Science seems to have answered all the big questions.
And yet, maybe we shouldn't be so cocky. For just as we have solved a hundred riddles about the natural world, so a thousand more have come to take their place.
That is why, in a new book, I argue that though many scientists think we are on the verge of knowing everything, they are wrong.
Here are some of the most intriguing questions science has not yet answered or, in some cases, even really addressed.
DO DOGS HAVE A SENSE OF HUMOUR?
I have always championed the cause of those brave men and women who risk injury and even death at the hands of animal rights terrorists by performing vivisection experiments that could save thousands of lives (including the lives of animals).
And yet, the more that scientists discover about the workings of the animal mind, the more they are forced to conclude that our fellow beasts are not mindless automata driven purely by instinct, but conscious, thinking entities capable of suffering and anticipation - and even humour - just like us.
Researchers have discovered, for instance, that elephants can recognise themselves in a mirror (something that very young children cannot do). Apes (and perhaps some birds) can learn the rudiments of English and make complicated tools. If crows can fashion hooks out of wire to help them fish food out of a jar, is it really right to conduct painful experiments upon them?
Some people say this is woolly thinking; that there cannot be animal rights without responsibilities. But this ignores the fact that we are happy to give many humans rights with no responsibilities.
The very young, the senile, the mad are given a legal status denied to any animal yet are also exempt from criminal and other sanctions.