Pharaohs and rovers sighted in homes throughout South Central Texas!
No, it's not a tabloid headline. The pharaohs aren't related to King Tut or Ramses, and the rovers aren't really too wild. However, these two diminutive ant species – found in pantries, on kitchen counters, and in and around sinks – can be a big bother for many South Central Texas residents, said Texas AgriLife Extension Service experts.
"These ants typically become more active in the summer," said Wizzie Brown, integrated pest management specialist for AgriLife Extension in Travis County. "Usually people immediately think any small, abundant ants making trails - usually to and from food or water sources in the home - are pharaoh ants, but they might be rover ants. Though different species, both types of ant are very small and move single-file in a row, so it's easy to be confused."
Brown said, however, that rover ants are darker - a dark brown or almost black color as opposed to the pharaoh ant's orange or rust color. Also, rovers are outdoor ants that come indoors searching for food and water - an activity that has become more prevalent with the region's prolonged drought.
"Pharaoh ants are also known as sugar ants due to their preference for sugary or sweet foods, and are also called pissants," she said.
While rover ants come indoors from the outside, pharaoh ants are already in the home, and only need a little encouragement to come out, Brown said.
"The pharaoh ant is really about the only ant you can call a strictly urban ant in that it usually lives indoors, making its home behind walls or under appliances or carpet," said Molly Keck, integrated pest management specialist in Bexar County. "They're often found going into or coming out of the cover plates of electrical outlets. The outlets make it easier for them to access interior walls and they can use the wires as their super-highway to your kitchen or bathroom."
Rover ants typically make their home in the leaf litter on roofs or in gutters or under rocks, stones or concrete, she added.
"While rover ants will eat sweet foods when they get really hungry, they seem to be most attracted to foods containing protein, such as dog food or meat," she said. "You'll more often find them clustered around a small piece of meat than something sugary."
Like other ants, rover ants that invade homes will often nest in damp interior walls around plumbing or near leaky window sills.
Keck said the diminutive size of both species makes them relatively unobtrusive - unless moving en masse in a long trail across a household surface - and that neither species has much of a bite.
Still, most people consider the ants a pest and are interested in ways to control them, Brown noted.
"Ant baits are the best method of control for both types," Brown said. "You don't want to use a spray on either of these species as that likely will split up the colony and ultimately lead to more ants in more locations," she said. "You need to be aware of differences in baits and the safest and most effective ways to apply or set them out."
"Typically there are only liquid baits or bait stations labeled for indoor use to control pharaoh ants, so you shouldn't go putting a pile of ant bait in your kitchen or bathroom," Keck warned.
Keck said she prefers to use a solid bait to control pharaoh ants and a gel or liquid bait to control rover ants.
"Rover ants can enter your house through weep holes, cracks or any other opening large enough to fit through," she said. "For better pest control, you should seal any cracks or openings around windows and doors as well as other possible points of entry.
"Outdoors, remove the remnants of any uneaten dog food, and trim the grass touching your house and the branches touching your roof as these may provide a means of access. Indoors, remove food sources - bread, cakes, chips, etc. - from kitchen surfaces and clean those surfaces thoroughly before using the bait."
Brown noted that removing alternative food sources makes the ant bait more appealing to the ants.
"But if the ants don't seem to be eating the bait, you may want to try a different type," she said. "For example, some ant baits are sugar-based and others are protein-based, so the effectiveness of the bait may depend on the type of ant and the sort of food the ants are seeking."
Brown said placing a bait station near the area where the ants appear to be most active is likely the best approach to control.
"But if you're using a bait, be sure to keep it out of the reach of children and pets, and particularly keep it away from places where your cat might be able to get to it," she said. She added that since pharaoh ants often enter and exit thought electrical outlets, taking the cover plate off and dabbing a small amount of gel bait in the wall void can be very effective.
"Many people think you have to put a lot of gel in there to do any good, but a small amount is plenty to be effective," she said. "Just remember to scrape off the old bait before putting on any new bait since the bait will dry and harden over time."
Brown and Keck both noted that while the ants are not a major health threat, they can potentially transmit disease and contaminate sterile materials - a particular problem in a hospital or similar setting where a high level of sanitation needs to be maintained.
"For both ant species, it's important that you choose the right type of control because of their ability to disperse and repopulate," Brown said. "That's why it is so difficult for some people to get rid of them. They're persistent and can re-establish quickly, so you have to manage them properly so they don't relocate and repopulate in multiple locations."