No, no, no. You got it all wrong. You want to study bedbugs...they stay near their hosts, hiding during the day, but when their victims sleep, they come out and suck their victims' blood.
And they are almost impossible to get rid of without chemicals like DDT.
Maybe some Demagogues are cockroaches, some are bedbugs, some are malarial mosquitos, and some are headlice.....