In the spring and summer the air was often full of buzzing and chirping sounds of insects; but now it is quiet.
Where are all the insects in winter?
Some, like monarch butterflies, have migrated to warmer places.
What do you think happened to the caterpillars of butterflies and moths that stay in your area? Have you seen any pupal cocoons in the shrubs?
Many insects laid eggs that will overwinter in the ground, under leaves or other protected places before hatching in the spring. After laying eggs, the adults died.
Have you seen any signs of these dormant stages?
Some tough invertebrates are active in the winter - like spiders and winter stoneflies. Have you spied any of those lately?