refugee squirrels!

[kriss]

A group of squirrels is living in our attic. I almost found the way they got in. So I thought of renting a live trap to catch them. So that I can seal their entry point.
Now I've done a bit of reading online and I understand these squirrel might have babies now because it seems to be months since they got here!
I couldn't find any smart way to check this out(for babies).
My husband seems to wish for calling some professional wildlife removal services. He already suggested an agency for the same. Should I prefer pros at this point? What do you think? Any recommendations or suggestions about the mentioned agency?