Not necessarily, but please note that:
1) You have 3 days to respond to the traveler's first message. If you do not respond, the conversation will expire. Most travelers apply to more than one host, to increase the chances of success. This means that if you take too long to answer, it is very likely that the traveler will confirm the trip with another host. So the fastest you answer, the highest the chances of confirming a trip!
2) It's important to send a friendly welcome message.
Maybe you loved the traveler's profile and you really want them to come, but if you answer something like "Hey Sarah, you're welcome" and nothing else, it doesn't seem legit or safe enough to the traveler. So, instead, try something more like "Hello Sarah, how nice that you are interested in collaborating at our place. I liked your profile and the dates you suggested are great. I will pre-approve your request and if you have any questions, just ask!"
Much better, right? ;)