I pulled open my toothbrush holder and out streamed hundreds of tiny black ants. I screamed and threw the plastic case, hitting a spiderweb. I felt like I was having a panic attack. I might have been. One theory is that your body releases histamine in response to a bite, setting off the itching reaction. When your histamine levels are too high, there is a natural release of adrenaline to counteract the histamine. Adrenaline can make your pulse race. They’ve also found high levels of histamine in the bloodstreams of people suffering from schizophrenia.