Chew cards are a safe and easy way to find out what predators are visiting your backyard.

They are filled with a non-toxic hypoallergenic lure that predators will nibble on. Each leaves a unique bite mark, meaning you can figure out what kind of trap is required to protect native wildlife in your backyard (and where to put it).

You will need

• Chew card
• Nail
• Hammer

Chew card ingredients

Chew cards usually include a paste with a non-toxic lure such as peanut butter. City Sanctuary uses chew cards manufactured by Connovation. They include a hypoallergenic synthetic peanut lure, icing sugar, flour, oil and blue dye.

Installing your card

Check the weather forecast. Ideally, put your card out when there are 5 to 7 clear nights in a row. Predators are less likely to be out looking for food if it’s raining.

Find the best place to put it. Start where you suspect rats or other predators might have been active — like near rubbish and compost bins. Try along a fence line, hedge or building.

Fold the card in half and nail it to a tree, fence or post. It should be at about knee height (30 cm) from the ground and the top flap should stick out at a 45 degree angle.

Leave your card out for 5 - 7 days. After your card has been out for 5 - 7 days, check it for bite marks. If nothing has nibbled your card, just take it down and move it somewhere else.

Whose chews?

Now it’s time for some detective work to figure out what chewed your card! When a predator bites your card it leaves a unique bite or tooth mark impression. For example, mice nibble on one side whilst rats chomp through the whole thing!

Use our guide to identify some of the more common bite marks.

Share your results

Let us know what chewed your card! Lay it flat on the ground, take a clear photo of both sides, and upload them here.