As of Monday night 86 rats have been killed at the Medicine Hat landfill. (Colleen Underwood/CBC)

Officials in Medicine Hat say the rat extermination program at the local landfill is going well, but they're still finding lots of the rodents.

As of Monday night, 86 rats had been found, but there may be hundreds more.

More members of the province's rat patrol arrived in the area Monday. Ed Jollymore of Medicine Hat waste management says it’s a learning experience for both teams.

"It really helps them learn how this colony is behaving. This is the first time that they’ve dealt with one in an area or an area as large as a landfill."

The rat burrow at the landfill was discovered last week.

"The [rat patrol is] bringing their expertise to help us look at our plans and review our programs and just having more people with a similar type of experience may see something that we’re not seeing."

Alberta spends about $350,000 a year on its rat eradication program.