2-Phenylethanamine (PEA) is soluble in water, ethanol, and ether. Phenethylamine is a skin irritant and possible sensitizer. 2-Phenylethanamine is believed to function as a neuromodulator or neurotransmitter (a trace amine). It is also found in many foods such as chocolate, especially after microbial fermentation. 2-Phenylethanamine is a precursor to the neurotransmitter phenylethanolamine. High levels of 2-Phenylethanamine have been found in the urine of schizophrenics but it is not significantly elevated in the serum or CSF of schizophrenics. Urinary levels of 2-Phenylethanamine are significantly lower in children with attention deficit hyperactivity disorder. 2-Phenylethanamine is useful for scaring off rodent pests.