A police officer said they have recovered the girl's mobile phone and were investigating the the cause behind the suicide.
The accused, forced to keep the body at his place due to the intensified police patrol in the area, blamed the dead rats for foul smell when neighbours enquired.
The source of the fire was recently discovered by the officials.
Boys tend to be callous and display unemotional traits because of difference in brain structure.
Meanwhile, Malvani police have registered an accidental death report (ADR) in the case. A post-mortem is expected to reveal the cause of death.
In an appalling incident, a 20-year-old woman was allegedly raped and then thrown off the fourth floor of a house in Delhi in a semi-naked condition by a man who was later arrested