heres a bit of info I've just nobbled;
Reduviidae is a large, cosmopolitan family of predatory insects in the suborder Heteroptera. It includes assassin bugs (genera include Melanolestes, Psellipus, Rasahus, Reduvius, Rhiginia, Sinea, Triatoma, and Zelus), wheel bugs (Arilus cristatus), ambush bugs (genera include Apiomerus and Phymata), and thread-legged bugs (the subfamily Emesinae, including the genus Emesaya). There are about 7000 species altogether, making it one of the largest families in the Hemiptera.
Adult bugs often range from 4 to 40 mm. They most commonly have an elongated head with a distinct narrowed neck, long legs, and a prominent, segmented "beak" (proboscis). Most species are dark in color with hues of brown, black, red, or orange. The most distinctive feature of the family is that the tip of the proboscis fits into a groove in the prosternum, where it is rasped against ridges there (a stridulitrum) to produce sound.
They use the long proboscis to inject a lethal saliva that liquefies the insides of the prey, which are then sucked out. The legs of some of these bugs are covered in tiny hairs that serve to make them sticky to hold onto their prey while they feed. The saliva is commonly effective at killing substantially larger prey than the bug itself. As nymphs, some species will cover and camouflage themselves with debris, or the remains of dead prey insects. Some species have been known to feed on cockroaches or bedbugs (in the case of the masked hunter) and are regarded in many locations as beneficial. Some people breed them as pets and for insect control.
Many assassin bugs have been known to bite humans when not handled carefully. For some species the bite is known to be very painful, sometimes causing allergic reactions, and bites can become infected, as with any wound.
Some blood-sucking species, particularly Triatoma spp. and other members of the subfamily Triatominae (e.g., Paratriatoma hirsuta) , are also known as kissing bugs due to their habit of biting humans in their sleep on the soft tissue of the lips and eyes; a number of these haematophagous species, located in Central and South America, are able to transmit a potentially fatal trypanosome disease known as Chagas disease (American trypanosomiasis).