5876 Hello, I live in North Bay Ontario Canada, right on the waters edge of Trout Lake I’ve seen these little pods all over the outside walls of the house, seems to be concrete or brick only though. The total overall length is no more that .75 of an inch and maybe 1/4″ to 3/8″ of an inch across. I assume they’re of biological origin simply because they’ve been attached to the wall. I’ve seen lots of posts elsewhere on the internet that talk about bagworms and show similar cocoons, although I haven’t read anywhere that they’re this small.
This looks like a case made by a grass bagworm, such as Psyche casta (Lepidoptera: Psychidae); see http://tinyurl.com/gt5arlr for some images. These caterpillars cause minimal damage to their host plants (mainly grasses). We often find similar cases on our house in West Virginia. Ed Saugstad, retired entomologist; Sinks Grove, WV.