WELLESLEY (CBS) – Wellesley High School math students received an unexpected visitor this week as a student accidentally brought his pet tarantula to class.

Wellesley sophomore Leon Xiong was in teacher Leah Burby’s algebra class on Thursday. Without Xiong noticing, his pet tarantula crawled out of his jacket while he was getting ready to leave at the end of class, The Bradford student newspaper reported.

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Xiong told the newspaper that he got the tarantula in January, but lost it this month when he was building the spider a new tank. The student believed his pet was loose somewhere in his house until someone in the class started to scream and he saw the tarantula.

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According to The Bradford, Burby got a cardboard box with air holes and wrangled in the spider.

“I was at my desk when I heard people screaming about a spider,” Burby told the school newspaper, adding that it was the strangest thing that’s ever happened to her while at the school. “I’m not afraid of spiders in general, and I thought this one would be very small. When I saw it, though, I thought it might have been poisonous, and got slightly scared.”

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After the spider was back in captivity, it was kept in the housemaster’s officer until Xiong could bring it home at the end of the day.