For every one of our Human years, Dog's apparently have seven 'dog' years; I was wondering if there is actually any scientific basis behind this or if it is just an urban myth??

Note:

Except for making sounds

This photo shows a green sweet that has been discovered by ants on a paved path in my garden. The sweet had been dropped several hours before, and had attracted the interest of an ant colony which was carrying it away. But the pattern of the surrounding plant debris is a mystery. What accounts for its arrangement around the candy?

Roy Levian, Lexington, Massachusetts, US

When I caught nits when I was younger, I remember trying to get rid of them by combing and chemicals. This was time consuming and, sometimes, uncomfortable. Wouldn't it be simpler just to drown them? If you can drown Headlice, how long would it take?

I always watch National Geographic movies and question myself: if you put a camera on the back of a seal, a penguin or some other underwater animals, does the animal even notice it, and does it hurt the animal?

Arthropods seem to come in any even number of legs above 4, e.g. 6 (insects), 8 (arachnids), ... and so on up to the very many legs of the millipedes.

But are there, or have there ever been, any 4-legged arthropods, and if not, why not? (Particularly given that 4 legs or fewer seems to do just fine for all higher animals)

I found the pattern shown in the attached photograph in the snow on my lawn on Christmas Eve.  I assume the two 'arcs' of straight lines were made by a beak, as the lines across the pattern appear to be bird tracks.  The arcs are about 20 cm apart.

If, out in 'nature', a broken bone pretty much garentees death by starvation, exposure or predators, is the fact that we have evolved self-repairing bones a fluke?

Most vertebrates have eyelids or some other means of protecting their eyes from strong sunlight, which would otherwise cause irreversible damage. Insects, and many other invertebrates, on the other hand, habitually sit or cruise around with their eyes, or parts of them, pointing upwards towards full sunlight, with no apparent adverse effects. Why does direct sunlight not damage their eyes?

As a supplementary, would photographic flash light damage the eyes of an invertebrate?