Multiple individuals of differing sizes found on top of plastic compost bin. The larvae can be distinguished by the well-developed head capsule (eucephalic), amphineustic spiracular arrangement (one pair in front, one pair at end), four lobes on terminus and oblique/vertical mandible orientation (seen in on of the pics). They are commonly found in the colder months of winter in rotting vegetable matter. These are probably in the genus Trichocera