I have no experience and my DS has just planted 150 bulbs; he is worried that they will get dug up. Any ideas?

They do, Hetty, and so do squirrels. But when you first plant tulips, they're usually at least 4 to 5in below the soil surface, so it would have to be a very hungry chipmunk to dig that deep. There are easier pickings around.

If he does start to see evidence of digging where he planted the bulbs, he could put up an easy- access bird feeder with seed to distract the critters from the bulbs.

He might lose a few, but not many before it gets cold enough for the chipmunks to hibernate. If he has a dog, or outdoor cat he won't lose any.

An extra inch or two of mulch will also help protect them. The deeper they are to start with the better they return years later.

I've had success with thwarting the vermin with chicken wire .. I'll place the bulbs then put enough soil to just cover, then lay down chicken wire and add more soil to the depth I need. I do this in pretty much all my beds now because of squirrels digging up seedlings.

I have had good luck by using medicated baby powder both on the bulbs and some on the soil above. This is also supposed to help with moles voles and grubs.

I only plant daffodils because the diggers won't eat those.

I agree with the chicken wire idea. You can lay it down flat, cover it with mulch and just leave it there. Not only will chipmunks/squirrels not dig through it, it keeps cats, dogs and other diggers out too. I have hens loose in the yard and they will scratch up anything, but the wire keeps them off. Stuff just grows right up through it.