Texas - Many people in Grapevine are wondering what to make of strange blobs at Lake Grapevine.

The Vineyards Camp Grounds have been closed due to recent heavy rains, but now Lake Grapevine has visitors popping and oozing up all over the place.

"Is it dangerous? What is it?" asked the Vineyards Camp Grounds employee Chad Hester. "Will it hurt me?"

Some have even called environmental agencies to report the globs.

Camper Kevin Mitchell said he has seen the globs "around a lot of the marinas, the docks, around the structures, trees, anything they can attach themselves to."

Park officials and universities have received dozens of calls reporting the invasion.

"They definitely had a concern. They wanted to make sure it was something that wasn't going to hurt them," said Joe Moore with the Grapevine Parks and Recreation.

The unusual blobs are actually freshwater invertebrates called moss animals.

In a press release, the City of Grapevine said each one "is a colony of millions of tiny organisms called 'zooids.' The colony exudes a protective gelatinous material that makes it resemble a big ball of jelly."

They cause no harm, and their presence signifies good water quality.

"They eat the microscopic plants and stuff that is floating in the water," said Moore. "They clean the water."

When they dry up, they turn into a paper like substance that crumbles and disintegrates.