@Whatawebsite not necessarily; imagine a creature capable of travelling through space at speeds we find unimaginable and a parasitic race which uses them to get around, I've seen this concept in a couple of places I think the magazine was called Starlord but it was also used in the TV series Farscape. Then all the parasitic species needs is a way of tagging onto the larger creature. How could a creature travel at those speeds? It is like us observing the speed of a humming bird which is incredible to the human eye. Humans have set limits on speed but these may not be hard rules.