Help make a nest for a local insect or bird by collecting, saving or otherwise organizing some valuable materials in a way that’s easy for the beneficiary to access. Think, “warehouse for animals who build dwellings”. You may use dry twigs, leaves, grass, straw, beeswax or fur from a cat or a dog (so long as they’re not treated with pesticides that remain on their skin). Abstain from using fabrics, plastics or human hair.
Place these materials in high, dry places; play with shape, size, color. Some examples include bouquets, symmetrical piles, rings made of twigs and CCTV cameras made of beeswax. Alternately, you may choose to scout a good, safe place for a nest and clean it if needed, carve small holes in wood for solitary bees or wet a patch of dirt to aid birds that build nests from mud.
Take pictures of your intervention. Waiting to see an animal use or at least examine the material or site is optional, you can always come back and look for traces of any interaction.