You are right to try to be VERY careful because hornets can be very
aggressive.

Looking at the pictures, you may have a few different options.

Here's a link with some information, although it doesn't quite describe your
situation. But it does talk about doing it at night, being careful with
using any flashlight and how to do that, etc.

http://unexco.com/gallery/hornets.html#diy

The idea of doing whatever you do at night, after it is totally dark out,
makes sense and I have done that. The main reason is that the hornets are
at home. If you kill them then rather than in the daytime, you won't have
to worry about returning hornets that were out during the day when you
sprayed, and which will keep trying to get back into the nest for a day or
two. It's best to hit them when they are all inside.

You may have some advantages based on the photos. If it's a screen door,
you may be able to spray through the screen from the inside and be
completely protected while you spray.

I see the tube through the door that you used to pour ammonia down onto the
steps etc. Ammonia etc. won't work. You need a chemical pesticide spray.
One of the best is any brand of hornet spray as others have suggested. The
hornet spray does stun them and knock them down when it hits them.

If it is possible to spray through the screen from the inside, I would do
that first -- at night, in the dark, with no lights on inside the room where
the door is. I would start with hornet spray. You may have a problem with
the spray splashing back on you as it hits the screen. Another option may
be to take the screen out, then either spray though the slats in the outside
door or maybe (at night) open the door, spray quickly down onto the steps
and cracks, then close the door quickly before they can get to you.

Or, you can do it from the outside -- at night. Get two cans of hornet
spray -- one for each hand. Cover up well, including maybe some kind of
veil over your head. Slowly sneak up fairly close to the steps, and don't
stomp around creating vibrations. Spray the steps where you know they go in
and out and along other cracks and crevices, and then leave the area.

I did this at night for a ground level nest of hornets. It worked fine.
They can't really figure out what to do fast enough to really get you at
night, especially if you don't have a flashlight in your hand. They don't
know where you are.


wrote:
I have a set of two wooden steps resting on concrete outside a door.
The structure is completely enclosed, but with lots of cracks where
hornets can get in and out.

I am afraid to try to remove any of the boards to gain access because
they are very aggressive.

In a previous post I was asked for pictures. You can see them at:
http://j7000.com/stairs/stairs.pdf

Any suggestions will be appreciated. Thanks.