WAUKEGAN, Ill. (AP) _ Animals looking for food or a drink in what looks deceptively like a pond are being killed by a sticky, contaminated black muck, and officials trying to clean up the oily pit are looking for someone to blame.

The swampy pit in an industrial area 60 miles north of Chicago holds a toxic chemical mixture that has snared scores of unsuspecting animals.

''It is instant death,'' said U.S. Fish and Wildlife officer John Brooks, who is studying the chemicals in the pit. ''It looks just like a natural pond.''

Eight blue herons, a beaver and several mallard ducks have been coated with the black substance that looks and smells like tar within the last year, according to Brooks and city animal control officials.

Blue herons ''make their living spearing fish. ... The bird will land, sink down and get the stuff on itself. It will try to preen or clean itself and it gets the stuff on its beak. Then it is all over. Once it is on the bird it won't come off,'' Brooks said in a telephone interview from his offices in Rosemont.

Other animals probably have died in the pond and sunk out of sight, Brooks said.

Several industries once operated in the area surrounding the pit, including a tannery, a concrete lamp pole manufacturer and a North Shore Gas Co. gas plant. A railroad track runs beside the pit.

Because so many industries set up shop in the area, city officials have been unable to find who dumped the chemical.

''I would like to have them clean it up voluntarily,'' said Jack Simonian, the city's governmental service director. But no one has come forward to do so, he said.

The Northshore Sanitary District, which owns the 16 acres on which the pit lies, is awaiting results of tests to identify the contents of the pit to determine if filling it in is feasible.

Wildlife advocates are uneasy about leaving the pit as it is.

Andrea Kane, a wildlife expert in Woodstock who tried to save two of the birds, said even if the animals had survived they would be unable to lead a normal life.

''Oily substances and chemicals that are toxic can be absorbed into the bird's system,'' Miss Kane said.

''I sincerely hope that they do something before a child falls into it,'' she said.