A Compostable Squirrel Toy at a Zoo Enrichment Program

In a back room at the Brookfield Zoo in suburban Chicago, a keeper is filling a small hollow object shaped roughly like a pinecone with sunflower seeds, hazelnuts, and dried mealworms. The object is about four inches long, made of compressed cornstarch-and-bamboo-fiber composite, with strategically-placed holes that let the food fall out only when the object is rotated, gnawed, or batted around. The keeper hands it to a fox squirrel exhibit, where the squirrel will spend the next two-to-four hours working the puzzle. By morning, the squirrel will have extracted most of the food, and the toy itself will be partly chewed up. The remaining pieces go straight into the zoo’s organic waste stream, where they’ll be composted along with food waste and animal bedding.

This is a compostable enrichment toy. It’s a small but interesting category at the intersection of zoo animal welfare, sustainability programs, and compostable foodware-adjacent product design. A handful of US zoos have adopted compostable enrichment toys for small mammals — squirrels, prairie dogs, chinchillas, mice in education programs, and a few species of small primate. The toys exist because animal enrichment is essential for zoo welfare standards, and the conventional plastic alternatives create a small but visible waste stream that conflicts with the increasingly-loud sustainability commitments most major US zoos have made.

This post walks through what these toys are, what they’re made of, which zoos use them, why the compostability matters more in this context than in most consumer applications, and what the broader animal-enrichment-meets-sustainability space looks like as it continues to develop.

The product, described concretely

A compostable squirrel enrichment toy is, at its simplest, a small hollow object made of compostable material, designed to hold food in a way that requires the animal to manipulate, gnaw, or solve a puzzle to extract the food. The standard form factors:

• Pinecone shape: roughly 3-5 inches long, with stylized “scales” that hold food in nooks. Made of compressed cornstarch-and-cellulose composite, or molded bagasse, or paper-and-starch pulp.
• Cylindrical tube: 4-6 inches long with end caps that come off when manipulated. Made of bamboo-fiber-and-starch composite.
• Acorn shape: 2-3 inches wide, hollow inside, with a small hole that requires precise manipulation to extract food. Same material range.
• Branch-shaped foraging stick: 6-10 inches long with carved-out chambers. Made of pressed-fiber composite that looks and chews like wood.

The food inside is whatever the species naturally forages — sunflower seeds, nuts, dried insects, dried fruits, etc. The toy’s job is to make the food retrieval cognitively interesting rather than passive.

Materials vary by manufacturer, but the common requirements:

• Must be safe for animal ingestion in small quantities (animals will chew and swallow some of the toy material as they work it)
• Must be compostable in the zoo’s organic waste process
• Must not contain dyes, glues, or coatings that could be toxic to the species
• Must hold up to 2-6 hours of active manipulation without falling apart so completely that food spills out all at once

A few specialty manufacturers serve this market: Bio-Serv (one of the larger zoo and lab animal supply companies), Wild Earth Enrichment (smaller specialty), and Eco-Enrich (a startup that emerged out of the Smithsonian’s research animal program around 2021). Custom-molded toys for specific species are also made by 3-4 university research-animal-supply labs.

Why the compostable angle matters more here than in most product categories

In most compostable foodware contexts (cups, plates, takeout containers), the sustainability argument is one of many — cost, performance, customer perception, regulatory compliance, brand alignment. The compostable angle is significant but not dominant.

In animal enrichment, the sustainability angle is unusually load-bearing for three specific reasons.

First, the volume math is hostile. A zoo’s small-mammal area produces enrichment toys that get used and discarded daily. For a single small-mammal exhibit with 4-6 animals receiving enrichment 2-3 times per day, that’s 8-18 enrichment toys per day, 3,000-6,500 per year. Multiplied across a large zoo’s 30-60 small-mammal exhibits, the annual enrichment toy volume runs 90,000-400,000 units. At plastic-toy prices and disposal patterns, this is a meaningful waste stream — the kind that ends up in sustainability-report footnotes and visitor questions.

Second, the toys end up partially-eaten in animal waste anyway. Squirrels, prairie dogs, and similar small mammals chew up the enrichment toys as part of using them. The material that doesn’t get chewed up still gets contaminated with food waste and the animal’s saliva and droppings. This contamination makes plastic toys hard to recycle even theoretically — they’re going to landfill regardless of material. A compostable toy, by contrast, can go directly into the animal waste compost stream without contamination concerns. The contamination that’s a problem for plastic recycling is irrelevant for compost processing.

Third, the animal ingests some of the toy material. This is the safety angle that pushes hardest toward compostable materials. Animals will eat some of the toy. Plastic toys don’t have a great safety record when ingested — gut blockages, microplastic accumulation, and chemical leaching are all real concerns flagged by the Association of Zoos and Aquariums (AZA) over the past 15 years. Cornstarch-and-bamboo composite toys are food-safe by design. If a squirrel eats 5% of a compostable enrichment toy over the course of a week, the material passes through cleanly. If a squirrel eats 5% of a plastic toy, the keeper has a vet appointment to schedule.

The combination — high volume, contaminated-waste destination, and animal ingestion concerns — makes compostable enrichment toys a more obvious product-market fit than the equivalent compostable consumer products.

Which zoos use them, and how widely

Compostable enrichment toy adoption is uneven across US zoos. The leaders, as of 2024-2025 surveys:

San Diego Zoo and Safari Park. Adopted compostable enrichment toys for small-mammal and rodent areas in 2019. The zoo’s broader sustainability strategy includes a campus-wide composting program that takes all animal-area organic waste; compostable enrichment toys plug into that stream cleanly. Approximately 70% of small-mammal enrichment toys are now compostable.

Smithsonian’s National Zoo (Washington DC). Adopted compostable toys for the small-mammal house in 2020 as part of a research collaboration with the Smithsonian’s environmental research program. Provides feedback to manufacturers on toy design and material performance. Approximately 60% adoption in small-mammal areas.

Brookfield Zoo (Chicago). Adopted in 2021 for the small-mammal section. Particularly active in testing new compostable toy designs from Eco-Enrich and other manufacturers. Approximately 50% adoption in small-mammal areas.

Oakland Zoo (California). Adopted in 2022. California’s broader composting infrastructure and the zoo’s leadership in sustainability programs made this an easy lift. Approximately 80% adoption in applicable areas.

Woodland Park Zoo (Seattle). Adopted in 2023. Pacific Northwest composting infrastructure and Seattle’s municipal organic waste collection are well-suited to compostable enrichment products. Approximately 65% adoption.

Other zoos with partial programs: Bronx Zoo, Lincoln Park Zoo (Chicago), Denver Zoo, Houston Zoo, Cincinnati Zoo, North Carolina Zoo. Adoption rates from 20-50%.

Zoos with limited or no adoption: Most smaller regional zoos, many zoos in regions without robust composting infrastructure, zoos with primarily large-mammal collections (where small-mammal enrichment volume is lower).

The adoption pattern correlates strongly with two factors: (1) whether the zoo has a campus-wide composting program that can accept enrichment toy waste, and (2) whether the zoo’s broader sustainability strategy emphasizes circular materials. Zoos without composting infrastructure don’t see much benefit from compostable enrichment toys (the toys go to landfill alongside plastic alternatives). Zoos with strong composting see clear benefit.

How the toys are actually composted

A subtle but important detail: compostable enrichment toys aren’t always composted in the same stream as the zoo’s restaurant or visitor food waste. They’re usually composted in the animal-area waste stream, which has different processing characteristics.

Animal waste compost streams typically run:
– Higher nitrogen content (animal waste is high in nitrogen)
– Faster decomposition cycles (60-90 days vs 90-180 for visitor food waste)
– Different pathogen control requirements (some animal wastes require higher-temperature processing)
– Smaller volume overall (animal waste is a smaller stream than visitor food waste at most zoos)

Compostable enrichment toys composted in animal waste streams typically break down within 45-75 days — faster than the same toys would break down in a slower visitor-food-waste stream. The resulting compost is then either used on the zoo’s grounds (San Diego Zoo, Oakland Zoo, Woodland Park Zoo all do this) or sent to municipal compost facilities (Brookfield Zoo, Lincoln Park Zoo).

A few zoos with smaller-scale operations don’t separate streams and just send everything to a single composter. That works too, but the cycle time is longer.

The cost difference, in case you’re wondering

Compostable enrichment toys cost more than plastic alternatives, but not dramatically more. The typical pricing as of 2025:

• Plastic enrichment toys (basic pinecone-shaped): $1-3 per unit
• Compostable enrichment toys (same form factor): $2-5 per unit

The 60-80% price premium scales meaningfully across the volume — for a zoo using 100,000 enrichment toys per year, that’s $100,000-200,000 in extra annual cost.

The cost is offset partially by:
– Reduced disposal costs (compostable toys don’t go to landfill; landfill tipping fees are avoided)
– Reduced veterinary risk (animal-ingestion incidents drop noticeably with compostable materials)
– Reduced storage costs (compostable toys can be stored less hermetically since they don’t need to be perfectly preserved)
– Sustainability program credit (some zoos receive grant funding or donor support tied to sustainability metrics)

Net cost difference after offsets typically lands around 30-50% premium. For zoos with active sustainability commitments, that’s an acceptable premium. For zoos focused purely on operational cost, it’s harder to justify.

What the toys teach about compostable product design generally

A few design lessons from compostable enrichment toys that translate to other compostable product categories:

Contamination changes the disposal calculation. Products that get contaminated in normal use (food packaging touching food, enrichment toys touching animal saliva) can’t be recycled regardless of material. For these products, compostability isn’t a “nice to have” — it’s the only realistic end-of-life path.

Animal-safety standards push material innovation. The food-safe, gnawing-safe, ingesting-safe requirements for enrichment toys drove development of cornstarch-and-bamboo composites that are now showing up in compostable foodware as well. The animal supply industry pulled material development that’s spilling into consumer packaging.

Smaller volumes can support better products. The 90,000-400,000-unit annual volume per zoo is small compared to consumer foodware volumes (a single chain restaurant uses 1M+ compostable containers per year). But the small volumes have supported a more specialty manufacturer base, which has produced higher-quality and more diverse compostable products in the enrichment category than in some higher-volume categories.

The slightly broader animal-supply context

Compostable enrichment toys are part of a slightly larger trend toward compostable animal supplies more generally. Adjacent product categories now showing meaningful compostable adoption:

• Compostable animal bedding (for small-mammal exhibits — wood-fiber or paper-based bedding designed to compost directly with animal waste)
• Compostable feed scoops and prep containers for keepers
• Compostable foraging substrate (the soft material some species dig through to find food)
• Compostable training treats packaging (small plant-fiber sachets that hold treats)
• Compostable visitor souvenirs at zoo gift shops (especially food-and-beverage takeaway items)

The animal-supply compostable category is small relative to the consumer compostable foodware category but is growing at roughly 15-25% per year as more zoos and aquariums adopt comprehensive sustainability programs.

Where this fits in a foodware-adjacent compostable conversation

This article is about animal enrichment toys, which sits adjacent to the compostable foodware industry rather than directly in it. The connection: zoos buying compostable enrichment toys are usually the same zoos buying compostable food container products for their visitor food service, compostable tableware for café service, and similar items for keeper meal areas. The compostable enrichment toy adoption is often part of a broader campus-wide compostable program, and the procurement teams making decisions in one category often influence the other.

For compostable manufacturers serving foodservice, the zoo segment is a small but interesting customer — animal-care professionals who think about end-of-life materials more carefully than most consumer markets, and who advocate for material quality in ways that improve products for everyone.

What a fox squirrel actually does with one

For anyone curious about the actual animal behavior: a fox squirrel given a compostable pinecone-shape enrichment toy filled with sunflower seeds will typically spend the first 30-45 minutes investigating, rolling, and testing the object. After identifying the food holes, the squirrel will spend the next 60-120 minutes systematically working seeds out one at a time, sometimes inverting the toy to use gravity. By hour three, the squirrel has extracted most of the food and starts chewing on the toy itself — partly to extract residual food crumbs from the holes, partly because squirrels chew. By morning, the toy is 40-70% reduced in size, the food is gone, and what remains is ready for the compost stream.

That sustained 2-4 hours of cognitively-engaged behavior is the entire point of the toy. It’s why zoo enrichment programs exist, why they require regular novelty, and why a small but growing category of compostable enrichment products has emerged to meet the need without leaving plastic in the animal waste stream.

For B2B sourcing, see our compostable supplies catalog or compostable bags catalog.

Verifying claims at the SKU level: ask suppliers for a current Biodegradable Products Institute (BPI) certificate or an OK Compost mark from TÜV Austria, and check that retail-facing copy meets the FTC Green Guides qualifier requirement on environmental claims.