I'm with Knot Sew - I think it's better to get a wildlife expert to come and relocate the nest if possible and if you have a problem with it being there. We had a hornets nest in our chimney last summer and I was concerned for the children so I did some research. They are not as agressive or nasty as you might think. They WILL sting repeatedly but only if provoked and if they don't have the option to fly away. Sadly, we had to destroy the ones nesting in our chimney when winter came because the flue was blocked and we couldn't use the fire. Up until then it stayed. Occasionally, we had one in the room, but I just opened a window and gently shooed it outside. If the nest had been outside, I would have let it alone.
I feel we are too keen to destroy wildlife without any thought to the ecosystem - every creature has a place and a role to play. And it's important to educate children in this and not make them afraid or feel that they have to kill everything that moves. They have to learn respect yes, but not fear or hatred. Just my opinion. :D