How do I make sure there are no birds inside the outside vent opening before blocking it with a mesh net?

A bird has gone into the vent opening on the house exterior and may have nested in there. How can I make sure I don't kill any birdies before I place a metal mesh net to block any more birds going into it in the future? I don't want to just stick my vacuum in there, lest I may kill any birds already in there.How do I make sure there are no birds inside the outside vent opening before blocking it with a mesh net?
Have you looked in there with a flashlight? If it looks clear place the mesh and check back periodically to ensure that no ones wanting out. 2 or 3 times over the course of a week or so!How do I make sure there are no birds inside the outside vent opening before blocking it with a mesh net?
Depends on the birds. Talk to a local landscaper. You can look at http://www.1800topsoil.com to see if they service your area.
a small amount of pepper spray. However, this is just what I would do. I cannot recommend it to you.
How deep is opening can you see to end with a flash light? if so that's way to go, if not could use some thing to feel back there with and gentle poke make there feel some thing nest sure hitting nest would make babies peep then will know they are there, take vent out and check it and put back.
Get the broom and shake it around in there to make any inside fly out.Then you will know.I would put my cat in there,he will flush them out quickly....
Call up Big Bird from sesame street and ask his advice

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