What's red and bad for your teeth? A brick. What's blue and bad for your teeth? A blue brick. What's black and bad for your teeth? Cavities. What's spherical and bad for your teeth? The spherical tooth destroyer. What was the chicken's name? Tooth. Why did the chicken cross the road? To escape the spherical tooth destroyer. Why did the chicken stop crossing the road? It saw that the building on the other side was made of red bricks.