Most reports of animals being found in fresh produce involved frogs, according to a University of Illinois study.

More than 50 percent of 40 incidents involved frogs, but lizards, snakes, mice, birds, and a bat, were discovered in salad greens, green beans, or mixed vegetables. Ten of these – nine frogs and one lizard – were alive.

Researchers reviewed online media coverage of wild vertebrates found in prepackaged produce by customers in the United States. They discovered 40 incidents since 2003 with 95 percent occurring during 2008 to 2018, suggesting their frequency may have increased in the last decade.

At least seven incidents involved Pacific Treefrogs and for three it was Green Anoles. At least two frogs were released into non-native areas. Six rodents and three birds were also reported.

Likely underestimate

Most reports involved amphibians (52.5 percent) and reptiles (22.5 percent), while fewer contained mammals (17.5 percent) and birds (7.5 percent), according to the study published in Science of the Total Environment journal.

“There’s a big food safety concern about any wildlife that gets into fields wher fresh produce is grown, leading to various control measures, sometimes even drastic tactics,” said Daniel Hughes, postdoctoral researcher in the Department of Animal Sciences at the University of Illinois and lead author.

Hughes believes the 40 incidents underestimates the true scope as consumers may report issues directly to the store or produce company and not to media, or stories may have appeared in newspapers and not been published online.

In three-quarters of incidents, the produce was conventionally grown, not organic.

“It was implied over and over in these articles: if you buy organic, getting a frog is par for the course, essentially. If that was true, we should have seen the opposite of what we found. We did not take into account market-share differences between conventional and organic produce, but this result ran contrary to common opinion,” said Hughes.

Incidents were reported from 20 states and eight had at least two issues. Texas and Florida recorded the most with five each and California and New York had four each.

Rabies risk as bat found in salad

Media reports did not suggest whether the presence of animals in produce constitutes a food safety crisis or was more of a food quality issue. Eight incidents of preserved produce, frozen or canned, were from conventional sources and all animals were dead.

alerts were not directly linked to outbreaks of foodborne illness and only the bat incident prompted a recall, while others led to apologies or offers to replac the product or refund customers. In April 2017, a dead bat was found in packaged salad from a grocery store in Florida. Fresh Express recalled some cases of Organic Marketside Spring Mix distributed to certain Walmart stores.

The CDC recommended post-exposure rabies treatment for two people. The virus wasn’t detected in remains of the animal found in the bagged salad.

Currently, many operations prevent animals from getting into fields by destroying non-crop vegetation near fields using “scorched earth” tactics. With information about wildlife getting into produce, farmers could adopt less drastic management strategies such as testing new fencing materials to exclude frogs from fields.

Hughes hopes to create a public portal for consumers to report incidents.

“If we could better track these incidents, it might be possible to detect geographic clusters wher frogs or other small animals are more common, or times of year they’re more active. In those areas or times, it might be as simple as changing the crop rotation schedule or the produce variety to one wher the animals can’t hide as easily.”

Automation and speed are other factors to consider and Hughes said it was hard to screen for animals due to industrial-scale harvest speed and volume.

“You’d have to spend minutes checking each plant. Romaine, for example, is lettuce folded on lettuce, wher it’s easy for moisture-seeking frogs to hide. From a business perspective, can you really spend minutes to check each leaf?”