Alphabetical List of Critters - Ambush Bugs and Assassin Bugs
Ambush bugs and assassin bugs are both in the family Reduviidae. Ambush bugs are technically a type of assassin bug. They are all chunky bodied insects of angular form. Most species of both types are also carnivorous hunters of other insects (and occasionally spiders), and have a thickened front pair of legs used to grasp and hold on to their prey (very much akin to how a praying mantis uses its front legs), and they each have a short beak that projects from the front of the head.
Some assassin bug groups specialize on certain kinds of prey, such as ants, termites, or millipedes, and some blood-sucking species, particularly Triaoma 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. Fortunately, kissing bugs are not found in our part of the world, but instead are mainly found in the Americas, with a few species present in Asia, Africa and Australia.
Detailed Fact Sheet: Ambush Bugs and Assassin Bugs (University of Kentucky) (includes photos)