Miner bees are solitary, ground-nesting bees that are gentle pollinators and play a vital role in ecosystems. Each female excavates her own burrow in loose, sandy, or well-drained soil, creating individual cells for her eggs. She provisions each cell with nectar and pollen before sealing it. That is what this bee was doing in the above photo. She went underground for a while after I took this photo. Earlier, she had been carrying a yellow pollen ball in her mouth to bring to her nest. To read more about miner bees: https://waspworld.com/miner-bees/

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I only mention the specific petunia pot in which this was occurring for my own future reference. The plant has nothing to do with the bee's behavior - other than potting soil being workable and this pot deep.