CHICAGO BUILDING CODE RE: PESTS
13-196-630 Residential buildings – Responsibilities of owner or operator.
Every owner or operator must:
(a) Comply with the requirements imposed on him by this chapter;
(b) Maintain in a clean, sanitary and safe condition the shared or public areas of the dwelling or premises, and maintain and repair any equipment of a type specified in this Code which he supplies or is required to supply;
(c) Exterminate any insects, rodents or other pests in any family unit, if infestation is caused by the failure of the owner or operator to maintain the dwelling in a ratproof or reasonable insect-proof condition, and he must exterminate such pests in any family unit in the dwelling, regardless of the cause of infestation, if infestation exists in two or more of the family units in the dwelling or in the shared or public parts of any dwelling containing two or more family units; and
(d) Supply and maintain the facilities for refuse disposal which are required of him by Section 7-28-220.
Learn more about tenant remedies for pest infestation here: https://www.tenants-rights.org/apartment-conditions-and-repairs-faq/