Caln Township Police said the protective sweep was conducted with the Chester County district attorney's office and the Chester County sheriff's office.
Police say several K-9 officers alerted to several areas, but no drugs were still present.
"This crime was shocking. We are all fortunate that no child was harmed," Chief Joseph Elias said in a written statement.
The boy's grandmother, 56-year-old Pauline Bilinski-Munion of Woodland Avenue in Modena, is facing endangering the welfare of children and drug charges.
According to the District Attorney's Office, Bilinski-Munion is a heroin user who had left heroin out in her home while taking care of her grandchildren.
The boy allegedly found the drugs and brought some of it into Caln Elementary School on Friday. The DA also says the boy distributed the heroin to at least one other child.
A teacher at the school learned of the drugs and later found nine bags of heroin in the boy's pants pocket.
The child initially claimed that he found the heroin in the school yard, but he later admitted that he brought the drugs from home, the District Attorney's Office said.
The drugs, which were branded with the words "Victoria Secret", were turned over to the Coatesville Area School District police.
A search warrant was executed at the residence on Saturday evening, and detectives allegedly located heroin bags in the home, as well as an empty heroin bag in a pair of children's shorts.
Bilinski-Munion was arrested on Sunday and is being held on $25,000 cash bail.