Insect and Spider Identification: CLOSED: Leaf-shaped cocoons with worm-like bug inside, 1 by drex82

drex82 wrote:
Hello,
Several of these leaf-shaped cocoons have appeared in my house bathroom. Some were in the shower and the one pictured was affixed quite high, approximately 5.5 ft from the floor, on a bathroom door. I am not sure how it got up there unnoticed. I nudged it and it began to move. A worm-like bug came out of the top end and began stretching out and moving the whole cocoon across the door, albeit very slowly. After a while, the worm went back into the cocoon, then emerged from the bottom of the cocoon and began exploring and moving again. The cocoons I found ranged from approximately 3/8 inch to about 5/8 inch in length and about 1/8 inch wide. The worm was very small, maybe 1mm in diameter.

What is this bug? Should I be concerned about a developing infestation?

I am located in Southern California.

Thanks.