Sea slugs, such as Elysia chlorotica, are small marine creatures that produce energy from sunlight - just like plants.

Elysia chlorotica can exist and photosynthesize similarly to a plant because it has the ability to use the chloroplasts ...

Simply install dim, red-spectrum solar lights near vulnerable plants; any slugs infiltrating your yard will avoid them. However, you will need to ensure that your lights are properly positioned.