hy you think a parasite, like a mosquito or headlouse, does not normally kill its host

Parasites, such as mosquitoes and head lice, typically do not kill their hosts for several reasons:

1. Sustenance: Parasites rely on their hosts for food and other resources. If the host dies, the parasite loses its source of sustenance.

2. Habitat: The host provides a habitat for the parasite. If the host dies, the parasite may lose its home.

3. Reproduction: Many parasites use their hosts to reproduce. If the host dies, the parasite may not be able to reproduce.

4. Transmission: Some parasites need their hosts to be alive to transmit themselves to other hosts. If the host dies, the parasite may not be able to spread.

In summary, it's in the parasite's best interest to keep its host alive for as long as possible. Killing the host would be counterproductive to the parasite's survival and reproduction.