Yes, they can. Bedbugs are lethal insects who survive on a human. There has been a debate as to why they invade homes, with some suggesting dirt others attributing to dumbness and still others argue that bedbugs like a humid environment. Whatever the case, bedbugs are destructive, dirty and health-endangering insects. There are a number of things that you need to be aware of when it comes to bedbugs. Knowing these things will help you avoid these insects completely from your home if they have invaded already. Consider this:
Bedbugs are not a sign of cleanliness. Otherwise, if a bedbug is seen in a broad day light crawling on your cloth, you will be deemed dirty and disorganized amongst your friends. It is unfortunate that these seemingly small insects appear in homes mostly at night, but at daytime, they will be seen on a person’s body!
Blood stains that they suck from human beings, is almost all there is in their bodies once they are crushed. If this happens on your clothes, it will be a permanent stain otherwise; your lovely cloth will have been rendered useless by a blood stain.
It has not been proven whether bedbugs cause any particular disease. This does not render these insects harmless. Bedbugs are suspected to be potential carriers of deadly vectors which are responsible for the cause of an infectious Chagas disease. Whether this is true or not, the fact is that bedbugs help in many ways to spread infectious diseases among those they suck and bite.
Bedbugs have the ability to pass through almost anywhere in order to reach their next prey. They have the ability to stay quiet feigning dead to escape the wrath of their attacker.
Whether they can pass in to your house through the vent, depends on what the vent is used for. Of course, if it is not to remove out smoke, they will comfortably invade you through it.