Where have our Alliums gone?

It depends on the height of the fence and what it is made of.

They can also, sort of, climb fences but rarely do so. We've seen them, the other side of the field, grab the top of a fence with their front paws and kick themselves over with their rear ones.

If it is made of wire they have more difficulty as they have problems actually seeing it as their vision range of colours is limited. We stopped them after a couple got in the garden over our short rabbit fence by adding chicken wire to the top, up to 6ft, with the top tension wire slightly loose. So if they try to grab the top it wobbles backwards a bit and they don't like it.

I got that wobbly top idea from another admin we used to have on here when he extended his wooden fence to stop his cats getting out and other cats getting in.

If they are Muntjac deer they can squeeze through a narrow gap, about 15".