An Ontario family was startled to discover more than the promise of their next batch of wine included in a crate of grapes, after finding a deadly black widow spider this weekend.

The foreign intruder was discovered on Saturday after Vito Gigli dumped a crate of California grapes, purchased from a Woodbridge, Ont., grocery store, into a wine press kept in the garage.

Giglio and his brother-in-law Donato Tersigni spotted the spider and, at first, didn't really know what to do.

"We were making wine in the garage. We had about 40 cases of grapes, and in the last case of the red grapes, that's when we found the black widow spider," Giglo told CTV Toronto's John Musselman.

"It was a little scary but at first we didn't know what it was. We put it in a jar and the kids looked it up on the Internet."

Tersigni initially said it was a black widow spider as a joke, but was shocked when the children found out he was right.

Black widow spiders are recognizable by the red hourglass stamp on their bellies. The species is known for being very poisonous.

But of the 30 kinds of black widow spiders, only three are venomous and generally only dangerous to children and the elderly.

The symptoms of a black widow spider bite are muscle cramps and stomach cramps that last a few hours to a few days.

Giglio has been making his own wine for years and never thought he would have to worry about what to do with a poisonous intruder. He said his family will call the zoo to see if they will take a deadly donation.

"I don't think it is a very good pet," he said.

Giglio said he has high blood pressure and isn't sure how he would react to a bite. He said he will be more careful with grapes in the future, and will have to buy some bite-proof gloves.

With a report from CTV Toronto's John Musselman