Read the following dialogue and answer the question!

Kiki: Ugh! These insect can't stop making noises on my ears.
Nana: I know right! When I sleep, they also do the same. Not to forget, they bite my skin!
Kiki: We can't see their teeth, right?
Nana: Yes! But they always leave red bumps, and in some cases, even bloods!

Which bug or insect do Kiki and Nana talk about?