Help with texting crush?

-Why do some guys wait to text a girl back? For example, the guy I'm talking to, we'll be texting for hours, and then he'll say something that I feel like doesn't need a response, so I won't say anything and I'll wait for him to text me again, which will sometimes be days later. Is that the wrong thing for me to do? Or should I text him something again? And what's an appropriate wait time in texting him, in regards to waiting however many days after not responding to his text? Idk, like I like talking to him, but I don't want to seem annoyingWell maybe you should just be like ok? Or like ..... Or just tell him ummmm I don't know what to say. Because he prob won't respond to nothing. Hope I helped good luck

:)))