This story starts for me long ago in an english lesson on ts elliot. A line which goes 'i should have been a pair of ragged claws scuttling across the floors of silent seas' was being discussed and my teacher made a point of the fact that crabs walk sideways and nobody quite new why and this was significant in understanding the poem.
Years later i happen to see a program about robots in which it was revealed that when designing a robot to clear mine fields it was discovered that an eight legged machine that walked sideways was an efficient way of covering the field without missing a spot.
Now i knew that crabs are scavengers and feel for food with their feet so i immediately made the connection that crabs walk sideways because they are searching for food and dont want to miss any. Presumably if you were to examine a crabs footprints you would see an even spread of dots.
Having just done a google search i find that this is not readily given for the reason that crabs walk sideways. I wonder If I am right!
I think this is quite interesting and may be worth exploring on your lovely program. Not least to hear Stephen Fry sum up with the line;
crabs walk sideways because they are bottom feeders!