"Only in Cornwall would you have to evacuate @Tesco because a seagull flew in," the Twitter user wrote.
The seagull was eventually captured and released outside the store.
A worker at the store told ITV they were unaware of the seagull "until it nearly flew into my head."
The employee confirmed that the bird had flown into at least one customer's face.
"As far as I'm aware she was not injured just a little bit shocked and who wouldn't be, no-one expects to go into their local Tesco and be greeted by a peed off seagull," the worker said.
Only in Cornwall would you have to evacuate @Tesco because a seagull flew in 😂😂 pic.twitter.com/co8eWevGEA— b.hutch (@_bradhutchinson) August 16, 2016