苍蝇见了血

苍蝇见了血

Literally means:

be obsessed with something like flies that see blood

Actually means:

When flies see blood, they will suck on it immediately and will not be driven away.

Figuratively, it means that people are obsessed with or addicted to something as flies are attracted to blood.

It connotes a sense of disgust. Derogatory.

苍蝇见到血，会成群地叮在上面不离开。

比喻一窝蜂地对准某个目标，或死叮着目标。

常含厌恶的意味。具有贬义色彩。