I can bait traps on 1 animal sanctuary and not get a thing. They get all sorts of stuff donated by local supermarkets but bread seems to be popular. every trap baited with bread will catch.
Go along with bread, friend had plague of mice, vacant ajoining house seemed to be source.
Bread they left out open but wrapped was nibbled. Yeah I suggested a bread bin !
Knew something bigger was around after whole wrapped loaf was dragged about 6foot along work top and 'opened' with almost child like semi circular bites out of discarded slices, baited rat trap with bread, took bait few times without setting it off. Finally got the bugger, it was about 16" nose to tail and body thick as my forearm. As others have said, see what they are feeding on & used to locally. Finally tally 17 mice + rat after week with 3 mouse & 1 rat trap. Mains Sonic rodent device has kept them clear for last 3 yrs.
In my own property mice had opened and eaten tea bags and induvidual porridge packs. Baited traps with few tea leaves and sprinkling of oats/ tea leaves on bait tray and few bits around trap, that sorted them out. Again sonic device kept clear since.
Partners son and my Aunty swear by Mars bars in their traps, bought specially. Said why waste money buying Mars bars, I want to kill'em not feed 'em