There’s a new mystery. Not crop circles or UFO sightings, but unidentifiable masses appearing inside our house.

They look like dried seaweed, hardened with a swoop. They break apart like compostable planting pots that you can sink directly into the dirt.

The cats claim to be innocent and aren’t even very interested. We look to the ceilings. What are these clumps suddenly appearing in the upstairs hallway as though dropped from above?

If I found an unknown plant, I could take it to a master gardener; a fossil or insect I could take to identification day at the Burke Museum. If I’d spotted an animal, I could photograph it and decide nutria or water rat.

But, these gritty things don’t have eyes, teeth, tails or claws. Our only clue – the objects appear when the windows have been opened on two sides of the house to allow a breeze.

I don’t know whether to consult an ornithologist or an exterminator.

As a reader, I cut my teeth on Nancy Drew and soon advanced to Agatha Christie and Ed McBain. In the absence of surveillance tape, I was going to make observations for myself. So, I crossed the street, inconspicuous as always in my pink bathrobe, and studied the block from the other side.

At first, it seemed that only flower petals and porch chimes were in motion, and then my eyes adjusted as though to see more color. On second glance, there were birds almost everywhere, despite the fact that no one on the block has a designated “backyard wildlife sanctuary.”

On the telephone and electrical wires that string our houses together like Cat’s Cradle were baby goldfinches, looking more greenish than yellow, fluffier than the adults. An adult male goldfinch swooped onto the roof of the garage to check my peas.

A pair of pigeons sat on the chimney cap of a neighbor’s roof, while the bush below the gutter teemed with chickadees. There were immature robin red-breasts all over the lawn, looking as plentiful as grackles. Could they be the bearers of brown objects through the windows?

I was sure that it had to be birds. Wouldn’t the cats stir if a raccoon was in the house?

I crept to the back of the house, having added a pair of binoculars. If the front yard had been busy, there was a traffic interchange in the back.

The Royal Anne cherry tree was bobbing with more robins, those that weren’t swinging below them eating raspberries. A flicker tried to chase off another American goldfinch, but then the black-and-white kitty from the corner leaped out of the shrubbery to send them both flying off the lawn.

I’m not a bird-watcher or a bird-feeding type, despite the fact that my mother has always been more diligent about feeding the birds than preparing food for her family. My mother was legend to my childhood friends for blazing a trail to the bird feeders barefoot in the New England winter.

She claimed that common birds were never the ones to hit our floor to ceiling windows; always the purple finch or the scarlet tanager. She would put the dead birds into plastic bags and stick them in the kitchen freezer to donate to Bird Sanctuary Museum in the spring.

But although we try to pretend otherwise, Ballard is part of the city. Sprinkling breadcrumbs or seed in the city has always seemed like just a way to attract possums, rats, raccoons, mice and the neighbor’s cat. Yet some of my mother’s love of birds got passed along.

It’s magic to be walking along and realize a bush is invisibly filled by those little flocking titmice. I never tire of chickadees, their pertness or their song. I love to watch the flicker take its long beak into the grass and pull out a worm as easily as a kid sucking on a straw. I’m tolerant of crows and seagulls because I know either of them could peck me to a pulp.

I’ve seen seagulls pluck clams from a pond and break them open by dropping them on blacktop. Is there a creature who thinks our splintery fir floors are just the right surface? For what?

The kitten finds the outdoors brimming with animal life, the little ants that are everywhere this year, gnats in the grass, flies and paper wasps. She doesn’t care about the snail farm that is along the damp retaining wall.

The snails leave criss-crossing trails that glisten on concrete in the morning light and look the dotted cutting lines on sewing patterns. Whatever is the culprit responsible for the strange brown objects; they don’t leave a trail.

Under my morning watch none of the robins, grackles, flickers, pigeons, chickadees, goldfinches or crows rout in the gutters. No animals shimmy up the electrical mast with kelp in their teeth. I don’t see any birds fly in, or out, of our windows.

I am no closer to solving the mystery, but don’t we all need to observe our surroundings from somewhat outside of our lives? If only to find out who or what else is living with us – wondering about the clutter we leave inside of their nest.