In the neighborhood I am in, I learned quickly NOT to invite the kids in.... and NOT to give them food.... so I followed the lead of what the dynamics were in the neighborhood. The reason I say NOT (in all caps) is this is not what the other neighbors do. Therefore, when I was doing it, it created problems. Without a relationship with the parents, you never know what they will think or do regarding their children being in your house or getting snacks. ( I had a parent confront me on the fact that they had food and didn't need mine) Uncomfortable!
I am not against having the kids in my home occasionaly but I think it isn't unwise to think about the fact that something could happen or could be said that could create a bad situation for all involved. I actually can appreciate and model not having children in my home or giving snacks, since this is something that could happen a lot. It gives me some space to breathe. I bought some crafts at garage sales and have gone out and chatted with the children and have done crafts with them.
Before I recongnized that other parents weren't having my children in my home, I had children in mine. Things were broken or things happened between the kids that were awkward. It really was a relief to realize the norm in my neighborhood is not to invite children in.
I empathize Quill, because it is a constant tension between how much time to I want the neighborhood kids to be here versus I have things I would like to do without feeling like I have to be congnizant of what is happening with the children that are over and how long are they going to stay? I can say that most parents do not come and check in on their children, so they could be at my house for long periods of time. I have learned to set in my mind about an hour and then I tell the kids we have other things going on. I have learned not to feel guilty about this. The other kids could hang out all day and no one would check on them. It seems like an hour of play works well but too much more that that, it all goes downhill.
Don't be afraid to set limits. It is your home and you are not obligated to entertain :)