The boy's father says on Monday he received the text with a photo that showed his 7-year-old son's head tightly bound with tape, but there was no message attached.
Rudy Yado of Sandusky tried to call the boy's mother, 31-year-old Tiffany Ennis. He then called police.
Police interviewed the boy at his school, then talked with his mom, who says they were just playing around.
Police say the child was not hurt.