Stag beetle (Lucanidae: possibly Ceruchus piceus) from Iowa, USA.
Male fire-colored beetle (Pyrochroidae: Dendroides canadensis) from Iowa. It has been shown that males of many genera in this family are attracted to cantharidin, the toxic chemical produced by blister beetles; in fact, they have been observed "licking" the cantharidin off of them! It is thought that the odor impresses females, to whom the chemical is transferred via a sperm packet and then used to give her eggs a protective toxic coating.
Burying Beetle, Nicrophorus sp. (Greek for "carrier of the dead") from Iowa. These aptly-named beetles bury small vertebrates as food sources for their offspring, which are taken care of by both parents - an extremely rare trait in the insect world.