Snails switch pace when the ground becomes too rough (such as a concrete surface) and would require a lot of creeping slime. By “loping”, they slow down a little, but save mucus.

The U.S. landscape is still dotted with enormous concrete arrows that guided early airmail pilots across the country. Barbara Mikkelson Published Aug. 29, 2013 ...

Researchers have developed a type of concrete that uses discarded shells. It’s now combating floods and food waste in urban gardens and along cycling paths. This time of year, bushels of rhubarb ...

So far, although the shells added to the concrete mix allow for improved porosity and compressive strength, and decrease the amount of aggregate used by 20 percent by weight, Williams and his team ...