like cats and dogs; dogs and monkeys
Idiomatic expression referring to a very bad relationship, akin to 'fighting like cats and dogs'. Literally 'dogs and monkeys', based on the traditional Japanese view that dogs and monkeys are natural enemies. Often used in the phrase 犬猿の仲.
See also: 犬猿
Those two are like cats and dogs.
They are always fighting like cats and dogs.
From the traditional Japanese belief that dogs and monkeys are natural enemies, giving rise to the idiomatic meaning of a very bad relationship.