A single word for non-domesticated animals that live among humans?

Synanthropic

:ecologically associated with humans
synanthropic flies

"Synanthropic." Merriam-Webster.com. Merriam-Webster, n.d. Web. 15 Oct. 2017.

Urban or urbanized might work, as in "urban wildlife".

This would refer to where the animals live rather than what their relation is with humans, and would specifically refer to densely-populated settlements.

e.g., it would clearly cover peregrine falcons in New York (which eat the pigeons that in turn eat our refuse), but might sound strange if you used it to refer to a wolf in rural areas preying on livestock.

Feral really means 'wild' but this word is often used to describe non-domestic animals living among humans.

Definition of feral

1 : of, relating to, or suggestive of a wild beast

2 a : not domesticated or cultivated: wild (feral animals)

Source: https://www.merriam-webster.com/dictionary/feral

Feral animals are wild animals that are not owned or controlled by anyone, especially ones that belong to species which are normally owned and kept by people.

Source: https://www.collinsdictionary.com/dictionary/english/feral

Real example: Yesterday I saw (on TV) a feral deer and baby which live in and around a North American township. This mother deer attacked and savagely kicked a dog which came too close to the infant deer. Luckily the dog survived the attack.

I would use the word "Cohabitant".

"3. to dwell with another or share the same place, as different species of animals."

From http://www.dictionary.com/browse/cohabitant

I feel this fits all the criteria you're looking for :)

The word you're looking for is commensal:

Commensalism, in ecology, is a class of relationships between two organisms where one organism benefits from the other without affecting it.

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