I wrote about house wrens a couple of years ago. In that column, I reported that the wrens of the neighborhood had spurned the very attractive birdhouse mounted on our garage. The male, I think, filled it with sticks, but the lady wren decided to nest elsewhere, so our house wasn’t used that year.

Last year, a male again brought in sticks — lots of sticks. When I cleaned out the box in the fall, I counted 556 of them, mostly silver maple twigs, averaging about three inches long. They were carefully arranged, piling up toward the entrance hole and sloping down to a nest cup at the back of the box.

One theory is that the sticks in the front part of the box divert any rain water down and away from the nest itself. It would also help fledglings find their way out of the box when they’re ready.

I also found the spider egg sacks he’d been bringing in that spring. It’s possible the spiders would help rid the nest box of mites and parasites that could afflict hatchlings.

But again, the box wasn’t used for nesting last year.

This year, however, it looks like a pair of wrens has taken up housekeeping in our wren house. He spends most of the day singing from nearby perches. She can be induced to poke her head out of the entrance hole if I walk by and make a squeaking sound with my lips.

“What kind of weird creature is attacking us?” she probably wonders.

House wrens are migrants who summer here in Minnesota but winter in the southeastern United States and into southern Mexico. They’re about five inches long, a mousy brown with barring on the wings and tail, which the wren often cocks up as it hops and flits about. It’s a very energetic bird.

I used to advise folks, before they put up a wren house, to make sure they liked the song. It’s a gurgling, bubbly song, pretty when you first hear it, but you will hear it all day long, all summer long, at times every five seconds.

I used to say that, but now I’ve learned to listen more carefully and have found that there are some variations in the singing. I’ve been trying to diagnose the song the male sings before he visits the house,  peeking in the entrance, perhaps delivering food, perhaps just to see how the incubation is going. But I haven’t found any unique pattern yet.

Wrens also have a scolding call they use if you get too close to them. My pal Val calls it their crabby sound.

I did learn that when the female visits the male under a nearby shrub, they engage in some soft chatter together — and perhaps something else. After all, those eggs do need to be fertilized before they’re laid.

Wrens don’t just love sticks for nest material. The other day I was sitting on the deck listening to the male wren serenading his box-bound mate from the bush, when suddenly he flew out of the shrub and landed in a bundle of sticks in the driveway.

These were tree branches and limbs I’d broken into six-foot lengths and tied into a bundle about two feet in diameter, waiting for yard waste collection the next morning. The wren hopped into the bundle, disappeared, popped out the other side, and was generally having a merry time exploring this temporary brush pile.

Wrens do like brush piles. When hiking through the woods, you’ll often hear one singing from a brush pile, but trying to see it presents a challenge. They usually sing from a perch, and while that perch is often out in the open, it can be down and in the shadows.

Speaking of shadows, house wrens do have a dark side. They aggressively defend their territory, not only from other wrens but seemingly from any bird that might compete for food.

Wrens often go after other nests in their territory, destroying them, piercing eggs and killing the young of competing nesters. They even get into bluebird houses and destroy the eggs.

It’s probably not fair to assign a moral value to either species, but killing bluebird eggs? That’s just plain wrong! But this is undoubtedly a trait that has evolved to make sure this pint-sized bird can get as much food as possible from its territory.

Wrens eat insects exclusively, so that’s a positive trait. And, if you can learn to love the song, you’ll be serenaded all summer long.