Yes, for many, it’s a very common outcome of physically interacting with them in any but the gentlest and most passive ways. It depends on the senses and nature of the bug, what it can notice, and what it’ll think of it. Flies very frequently start evading if you even move things toward them. Even gently bumping into most crawling bugs will tend to cause them to either evasively scurry away, run for someplace safe (such as a crack), or for some types, curl up or take other defensive postures. Some will also attack, which is generally a type of defensive fear behavior in most cases.