Final answer:
Fumigation and insecticidal fogging are used to control or eliminate pests in certain environments.
Step-by-step explanation:
When fumigating or insecticidal fogging is required, it is typically used to control or eliminate pests, such as mosquitoes or insects, in certain environments. Fumigation involves the use of gases or fumes to kill pests, while insecticidal fogging uses a mist of insecticide to target and kill flying insects. These methods are commonly used in situations where other control measures have failed or when there is a high population of insects.