Cats cannot excrete styrofoam boards they eat. If you find your cat eating styrofoam boards, it is important to stop it immediately, because styrofoam boards cannot be digested or broken down in a cat's body, so they cannot be excreted on their own.

Cats eating foam boards may be deficient in trace elements. This deficiency could be due to owners not regularly supplementing their cats' diets, or feeding them only one type of cat food. Although sellers may state that cat food contains trace elements, cats require a wide range of trace elements, and the amount in cat food is relatively small, failing to meet the cat's needs. Therefore, the cat may become deficient in trace elements.
Signs of Micronutrient Deficiency in Cats: Cats lacking micronutrients may exhibit indiscriminate eating habits, such as ingesting soil, wall plaster, wood, feces, plastic bags, and electrical wires. Owners should pay attention when they notice their cats eating these things. Some cats lacking micronutrients may also show signs of micronutrient deficiency, such as a white nose or even hair loss. Owners should carefully examine their cats' bodies. A normal cat's nose is typically blackish-pink with normal moisture.