In the opening scenes of TV's "Dexter", what annoying insect does Dexter kill at the start of his day?

The very first shot in the opening scene of the American TV show "Dexter" shows a mosquito. It is sucking blood out of the man's (Dexter) arm. He then slaps and kills the insect. The mosquito is a signifier; what is signified is the fact that it sucks blood. This denotes to the viewer that killing a mosquito is in fact good. Later, it is shown that Dexter's strong homicidal urges originate from when he was traumatized at age three by watching the brutal chainsaw murder of his mother, Laura Moser. That event made Dexter feel as if he was "born in blood" as a "monster". At age twenty, be began to kill and cut up his victims. His persona is one where he like a mosquito is always concerned with blood related issues.

"Dexter", a crime drama TV series, aired on Showtime from October 2006, to September 2013. Set in Miami, the series centers on Dexter Morgan (Michael C. Hall), a forensic technician specializing in bloodstain pattern analysis for the fictional Miami Metro Police Department. He is a guy who also leads a secret parallel life as a vigilante serial killer, hunting down murderers who have not been adequately punished by the justice system due to corruption or legal technicalities.

The show's first season was derived from the novel "Darkly Dreaming Dexter" (2004). It was the first in a series of novels by Jeff Lindsay. It was adapted for TV by James Manos Jr., who wrote the show's first episode. Subsequent seasons have evolved independently of Lindsay's works.