MERCEDES - A local rancher is warning residents to watch out for cows and horses running on Rio Grande Valley roads.

Teo Martinez, known as the Hidalgo County Cowboy, works with local police when livestock are on the loose.

He says he knows what's going on right now with the mosquitoes.

"This is the reason that the horses, cattle, animals, they get out from the property," says Martinez.

He says a fence isn't much of a barrier to a large animal that's seriously annoyed by the mosquitoes biting it; they can jump it or run through it.

He says the conditions were the same this past Monday morning when a driver hit four horses in a high speed Donna road.

The police investigating say they the horses weren't tagged and they haven't been able to identify the owner.

Martinez suspects the horses broke loose because of mosquitoes.

CHANNEL 5 NEWS visited Little Angie Agri-Products north of Weslaco.

Luis Lauro Martinez showed us a number of products they sell over the counter made for different animals.

He says they've sold record numbers of repellents recently.

For more information watch the video above.