Officials are warning pet owners to "take special precautions" as a historic cicada emergence begins in the city and suburbs.
The Cook County Department of Animal and Rabies Control issued an alert Monday saying pet owners will need to "protect the health and welfare of their pets this spring and summer as two different groups of periodic cicadas emerge simultaneously."
"This natural phenomenon hasn’t taken place in more than 200 years, as billions of cicadas are expected to emerge in Illinois in late May or early June," the alert stated.
Among the things officials said pet owners should keep in mind was the fact that cicadas might startle some animals.
"Cicadas do not bite or sting, are not toxic to pets and are not known to carry diseases, so interactions are generally safe. However, the noise, size and movements of cicadas may be startling to some pets," officials said. "If a pet seems scared, owners should try to direct them to an area with fewer cicadas like a comfortable and quiet place inside the home to relax."
They noted that dogs must be leashed when outdoors and that could help prevent startled pets from "accidentally getting away."
Consumption of the insects should also be monitored, the alert stated.
According to Allen Lawrence, associate curator of entomology at Peggy Notebaert Nature Museum, cicadas are going to be viewed as a tasty treat to many animals.
"As far as insects go, they're very large and meaty. They have a lot of nutrients there. That's a big meal just from catching one insect," Lawrence told NBC Chicago.
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But while cicadas aren't toxic to pets, there are still some potential concerns.
"While cicadas aren’t toxic to pets, gastrointestinal upset can occur if a pet consumes too many cicadas or their discarded 'shells' (exoskeletons)," the agency stated. "Intestinal obstruction or perforation could occur as exoskeletons move through the gastrointestinal tract, particularly if a small pet consumes many cicadas in a short period of time.
Owners will want to watch for vomiting, diarrhea, loss of appetite or excessive drooling and seek veterinary care if their animal experiences those symptoms.
"If your pet appears to be in distress, contact your veterinarian for further guidance," the alert said.