Police went to the restaurant to investigate and ended up arresting three employees.
The restaurant's manager, 30-year-old Tanisha Dancer, was arrested on an outstanding larceny warrant from another county. When police brought her to the jail, Fluck said officers found she was in possession of Ecstasy pills - the same kind found in the burger wrapping.
The other employees arrested were 35-year-old Jonathan Robertson, who had four outstanding warrants, and 22-year-old Jose Molina, arrested on suspicion of possession of marijuana.
The Taylor Police Department notified the Texas Department of Health, the owner of the Sonic location, and the corporate office of Sonic. Fluck said the Sonic director of operations told them that they have now fired Dancer.