What is this insect?

These bugs are somewhat plentiful in my garden, and I don't recognize them. We also had them last year. The other day one made it's way into the basement, so I was able to take photos.
They are almost half an inch long.
I noticed them for the first time this year about a week ago when I raked back some mulch from one of my flower beds, they'd been sheltering under the mulch.
If anyone has an idea of what kind of insects they are, thanks!

Those are Box Elder bugs.  We used to call them 'red-butt bugs' when I was a kid because you'll so often see two with their bright red rears stuck together during mating.

Although annoying when they break out in major numbers, they're pretty harmless. They feed mainly on maple species but I guess that they can feed on some of our precious fruit trees, too.  Damage is usually pretty minor.

Here's a nice little write-up if you're interested in learning a little more about them.

My Dad always told me that Box Elder Bugs are poisonous, if you eat them.

Excellent! Thank-you.