It depends. There’s such thing as exigent circumstances. If they believe that evidence could be destroyed before they get a search warrant, they believe there’s some sort of emergency situation, or if you’re on probation, then they don’t need a search warrant. They have to have articulable reasons.
The thing that gets confusing to people a lot of times is if you’re on probation, you’re subjected to a search at any time that they want to search you. If they find something, they can’t charge you with a new crime, but they can charge you with a violation of probation.
Law enforcement will ask “can I come in and search your house,” and a lot of times, people will say “yes.” If you say “yes,” they don’t need to go get a search warrant. They can search.