Like others have said, that mound is basically a vent shaft. Too deep to push the sod up, so they must get the dirt out of their way. When the vent becomes too far from where they're digging, they plug it with dirt and dig a new vent. So then you can use the mounds to connect the dots to determine the direction of travel. Typically the bigger the mound the deeper the run. Often the giant mounds are in dry conditions. You have two options then, dig down to the run, or water to bring the moles back to the surface.

A friend of mine told me the mounds are the result of a male digging a breeding chamber.. but he's also told me some other "tales" that have never proved out.
That said, we've had tones of rain this summer (like 5 inches in one week) but I don't see the tell tale tunnels as I did last year.
Gonna see what I can do with the "connect the dots" method. I caught 8 of the little demons last year and still have 3 or 4 creating havoc around here.

Thanks for the tips!

Since this thread is still alive, I'll post additional questions here. I set up another mole job today. This one is going to be more difficult than the last, as I could find zero shallow runs. But the mole hills were enormous! Runs were going downward at a steep angle as the job before, but this time I tried digging down to find where they leveled out, which ended up being around 14-18" down. Then I set OOS traps over these runs. My question is, can you not spook a mole by doing that much excavation? I still need to get some moleinator traps (Albano's) but TRapper said he uses OOS's exclusively, so I figured I would give it a shot. My work looks much worse than the mole hills though, lol. I'm sure the homeowner was concerned...

Roe - unfortunately, true Talpex mole traps are not available in the USA. Just like you guys in the UK, if I'm not mistaken, cannot directly buy Trapline Mole traps from Steve Albano. I've recently bought some true Talpex traps from Fourteenacre and some Talpex-type traps from Flatpack in the UK but the postage and handling fees (carriage?) are exhorbitant unless you're buying in large quantities!

Like a lot of mole catchers over here, I use mostly the upgraded Out-of-Sight and the Trapline Mole traps. I resort to the Talpex along house foundations, fences, driveways, sidewalks, etc. or anywhere I think Mr. Mole will dig under my sandy soils.

Definitely not on the breeding chamber thing...mounds are created when digging deeper horizontal tunnels...they have to put the dirt somewhere

A mole's main diet of earthworms plus secretions from its scent/musk gland makes for a not so tasty treat for the 4-legged predators. Pulling a trap with a mole always make me look for the natural gas leak around the house. That's what they smell like to me! I'm not too worried about losing my traps as much anymore.

I'm imagining a mole cartoon with a bulldozer blade on front. I don't think they push that much ahead of them....

The deep runs are still kicking my tail. Managed to pinch one today when it finally made a shallow run, as we've had a cool front mixed with precipitation the past couple of days. But it's taking too long. I did order a half dozen of Steve's traps a couple days ago, so I'm looking forward to trying them. I still don't exactly see how they wouldn't get prematurely tripped as the mole is pushing dirt up through the deep runs, but maybe it will make sense to me once I actually set one.

Hi, they don't push so much, they generally pull dirt back.

Best thing I ever did was get one of LT's mole trapping tools. It isn't good for real deep runs but for surface runs I can put in a set in about 10 seconds !
For carrying mole traps to a set? I clamp them on each other to form a ring and open them at each place. Try it, it's amazing how light it is. No need for a bucket ! LT taught me that trick. A real time saver !
Angela

I still like to bury the trap...guess it is a system i am good at...sure the tool helps lol