What does the cryptic crossword clue "Immature creature picked up from volcanic discharge (5)" mean?

The definition is "Immature". The wordplay uses a homophone (sounds like). sounds like ‘lava’ in non-rhotic varieties of English The answer is LARVA.

Immature creature picked up from volcanic discharge (5)

Times Cryptic #28897 | 6 Across | 2024-04-22 flower