There are a lot of manmade things in this world that go fast. Trucks and trains can reach speeds of hundreds of miles per hour, while spaceships can go thousands of miles per hour. But what kinds of things are the slowest? There are a number of animals that creep along very slowly, such as snails and tortoises. The slowest animal, however, is the three-toed sloth, which can’t move any faster than 0.003 miles per hour. That means they won’t travel more than 100 feet in a day.