PHILADELPHIA —  Customs agents seized more than two dozen giant beetles — some the size of a child's hand — from an overseas package after postal workers heard the insects making scratching noises.

The large bugs arrived last week from Taiwan at a post office in Mohnton, about 50 miles (80 kilometers) northwest of Philadelphia, in a box whose contents were labeled as toys, gifts and jellies, officials said Wednesday.

But the postmaster suspected the package contained live organisms and notified authorities, according to the U.S. Customs and Border Protection agency. The package was sent to Philadelphia, where it was X-rayed and then opened.

"The specimens were some of the largest of their kind, and some of the largest I've ever seen, averaging five to six inches in diameter," John Plummer, an agency agriculture specialist, said in a statement Wednesday. "They are highly destructive insect pests that can cause extensive damage to fruit and vegetable crops, trees, shrubs and turf grasses."

In all, authorities found 26 Hercules, rhinoceros and Goliath beetles. It is illegal to ship live beetles into the United States without a permit from the Department of Agriculture.

Seven of the beetles were in containers labeled by gender, which means they could have been intended for breeding, customs agency spokesman Steve Sapp said Wednesday.

The sender and recipient have been identified, Sapp said. An investigation is under way, but no decision has been made whether to file charges, he said.