A shark and his son were cruising the ocean when they spotted a sinking fishing boat, with the crew flailing in the water.
Dad said to son "Here's a feed for us!... just follow my lead, and we will both enjoy a good meal ... first of all we circle them with- just- the- 'tips' of our fin showing......and then we circle them again, with ALL of our fin showing... and then we eat!"
The son asked "Why don't we just charge in, and eat them right now?"
The father shark replied "Because you will find that they taste a hell of a lot better after they have voided their bowels!"