Spiders prefer to be in dark, dank places so that would be a good habitat for them. Your concern about Black Widows may be unfounded since they mostly stay away from places humans congregate. Most often we will clean someplace similar with a broom with the head covered with an old cotton T Shirt to sweep away the webs. I have seldom found it necessary to spray some kind of poison around, most of which now cause my asthma to act up.

Black widow spiders are easily identified...they can't be mistaken for anything else. I'd be certain of the identity of your critters, if possible.

I totally disagree with Kimmsr regarding the habits of black widows. Though they are not typically found INSIDE a home, they are a very common resident of nooks and crannies found in garages and all around the outside of homes, playgrounds, office buildings, pool houses, etc. I do not know where you are located, but black and/or brown widow populations have skyrocketed in some areas. Brown recluse spiders will often be found in the same kinds of locations as BWs, depending upon your location.

You'll need to do some good cleaning of the garage items before you move them into the house. Black widows (and other spiders) often overwinter in the form of little egg sacs that will be more than happy to hatch out in your warm home. Female spiders, if they are still alive and present, will often defend their egg sacs. BW spiders can be counted on doing so, but so can others.

Wear gloves and long pants tucked into your boots or socks while doing your cleaning chores. Each item should be inspected and wiped on an individual basis. Don't move stacks of pots into your home, for example, without separating them first. BWs and BR love love LOVE to set up housekeeping inside stacks of pots, lol!

How many people have been bitten by Black Widow spiders in the USA in the past year. The Center for Disease Control does gather this information.

Your point isn't a powerful one, considering the well documented behavior of the BW. They are loath to leave their messy webs and are not aggressive by any stretch of the imagination. They will only bite truly antagonized. If a human or a pet is bitten, the severity of the reaction is based on the individual. It is an experience that should, by all accounts, be avoided.

I can personally attest to the fact that one can work in very close proximity to dozens of these spiders and not get bitten. That fact does not mean that I will encourage or ignore their presence.

A local swimming pool in my city was closed for a short time this summer because BWs were observed under benches and tables, in the changing rooms, and in other busy locations. Hundreds of the spiders were found. Though no one had reported being bitten, the spiders most certainly had to GO!

Do spiders build webs (messy, thick ones) in trees? We have some above our garage... and I am not sure what they are...

What I think you have are not spider webs...we have those every spring and they are common tent worms...they turn into the fuzzy catapillars and really don't do anything but crawl around, poop and be food for the birds. I don't even know if they turn into anything. When they hatch you will notice a ton of them crawling around. They can be very messy to clean up...here in Manistee, Michigan we have had them so bad that driving down the road was nasty and scary..you could actually hear them popping sometimes when you run them over. I have actually driven on the roads when they were slippery from sooo many crawling aross the road and getting smushed....nasty. But the kids love to hunt for them and put them in a jar....I did hear that they make pretty good bait....I hope this helps you. Good luck...my dad used to spray them with lighter fluid and then let it and them go up in flames...but not so good when it is dry and the fire danger is high...