Increasing slug numbers are forcing grain growers in western Victoria to re-sow their crops.
Lake Bolac agronomist Cam Conboy says a wet autumn has boosted slug numbers, with yields at threat if left untreated.
"Baiting programs are working. The problem is some guys had to do one bait and that's worked successfully and others are up to four baits and are still struggling and are having to re-sow areas," he said.
"So it's really just a numbers game on how bad the slugs are, what stage of the lifecycle they're up to and trying to work out the appropriate strategy."
Farmers further north in the Wimmera faced mouse problems during sowing.
Mice at Dimboola were eating crops as quick as farmers planted them, forcing farmers to re-sow their early crops.
Mr Conboy says the slugs are causing bigger issues than mice in the western district.
He says farmers are also reporting issues with red-legged earth mites and cut worms.
Mr Conboy says mice are eating the slug bait without suffering any ill-effects.
"The problem is that the brand-based baits that we use for slugs are quite attractive to mice, but not lethal to mice, so the mice will eat the slug bait and then leaving areas exposed with no slug bait means the crop gets damaged by slugs," he said.
"So the mice are causing more problems by eating the slug bait than anything else."