Shellac is made from the secretions and bodies of a tropical insect, and it is used in varnish, as a wood and plaster coating and in electrical insulation, among other uses.
A small number of lubricants still use oil from fish and marine mammals, such as porpoises. However, most modern lubricants are derived from petroleum or synthetic oils.
Notably, WD-40 is not believed to contain animal ingredients. The all-purpose lubricant is a petroleum-based product despite a widespread urban legend about fish oil being the main ingredient. The WD-40 formula is a closely guarded secret, but the U.S. Material Safety Data Sheet lists mineral spirits, liquefied petroleum gas and mineral oil as making up more than 90 percent of WD-40.
Many fatty acids and other animal fat derivatives are used in soaps, detergents and household cleaners. The fatty acids may come from cows, sheep and many other animals, including cats and dogs that were euthanized in animal shelters. If ingredients are listed, animal-based fatty acids may be listed as caprylic acid, lauric acid, myristic acid, oleic acid, palmitic acid and stearic acid. Some of these fatty acids also have plant sources, so you may be able to use products containing them if you can verify the source.
Of course, many fertilizers use animal waste products, but a cow is unlikely to miss its manure. However, bone meal is also widely used in garden and lawn fertilizers. The ground animal bones are also used in toothpastes and vitamins, but animal-free alternatives, such as vegetable compost and vegan toothpaste, are widely available.
Laminated wood and interior doors sometimes contain adhesives made with casein glue, which is derived from a milk protein.
Another animal-based adhesive is blood glue, which is a slaughterhouse byproduct. It has traditionally been combined with soybean protein to make an adhesive for soft plywood. However, the formula has largely been replaced with a synthetic adhesive.
This is a partial list of home improvement products with animal ingredients. Keep in mind that not every paint or fertilizer contains animal products, but some do, and the animal content may be worth considering in shopping choices.