Vanessa atalanta rubria
Vanessa atalanta is a widespread butterfly (North America, Asia, Europe), and also a garden visitor, though I wouldn't call it "common". The coloration - the red stripes set against black - is striking, as is the detail on the ventral side of the wings. They feed on nettles, rolling up a leaf to form a shelter. They then feed on that leaf from the end until it no longer serves as much of a shelter, at which point they move on to a new leaf. Always a welcome garden visitor, where they may feed on baby's tears, which are also members of the nettle family.
The red admiral, Vanessa atalanta rubria, in my garden in Long Beach on July 13, 2005.
The underside of the red admiral makes for good camouflage. El Dorado Park Nature Center, February 7, 2006.
Finding folded-up leaves like this one means you have a good chance of finding red admiral caterpillars. This nettle patch in Idyllwild is good for this species. June 10, 2023.
In just a few minutes, I had five red admiral caterpillars, including these two. Like other Vanessa-species larvae, there are a variety of forms, but these are typical. Since then, I've been seeing them nearly every time I hike in an area with nettles.
One of my caterpillars pupated; here's the chrysalis. June 21, 2023.