I just spoke with an entomologist at SB Museum of Natural History, and he thinks they are Tiger Moth larvae.
Pretty cool! I will try to relocate them outdoors. Here's why:
While some moths, particularly caterpillars such as the corn earworm, are major agricultural pests, many others are important pollinators. "Their hairy bodies make moths great pollinators — they pick up pollen from any flower they land on," Moskowitz said.
Moth-pollinated flowers tend to be fragrant and white, such as the yucca plant. Plants with these features allow nocturnal moths to easily find flowers after dark.
Some moths pollinate by day. Hummingbird moths hover in front of flowers and unfurl their long tongues to sip nectar; they feed on a variety of flowers, including bee balm, honeysuckle and verbena.