The common term for this is mimicry. Take as one example - the similarity in the patterning of one of the sub-species of milk snake, which closely resembles the banded markings of the coral snake. The milk snake is completely harmless, while the coral snake is highly venomous.
An antonym for harmless is harmful.
no they are harmless
they are only harmful to humans if you attack their home and try to eat them.
harmful
Innocuous, harmless
harmful, destructive, evil
No they are harmless to humans
Black magic
The harmless animal passed by.
Without animal testing, humans would have a greater risk of dying if expirementing with products that people have no idea whether it is harmful or harmless. Personally I don't agree with animal testing, but what other choice do we have?
Mimicry.
Mimicry.