10 December 2021 12:03 PM
The grub in the photo provided is a Sawfly Larva. It is unusual for this insect to be venturing indoors, as they feed and dwell on plants. Given the recent wet weather lately, they could be seeking out a drier environment.
If they are a problem, find the plant they are coming from, and spray with Yates Baythroid Insect Killer for Gardens - please check label to ensure product is registered for the plant.