Answer: Immigrants crossing the border illegally are considered aliens.
Deep Dive | Why are Mexicans crossing the border?
The reason why immigrants cross the border illegally as the situation within their home country is unethical, forcing them to head for the nearest province quickly without regard to certain procedures that allow you to reach these provinces legally, but due them having family needs and needing status as asylum seekers they rush in without any regards to immigration procedures, which later on ruins any opportunities within the province they have chosen to reside in as they entered illegally.