Tulips usually only come back for a year or two. After that, you may get foliage but no blooms. Do a search for "perennial tulips" if you want a list of types that do come back more readily.

Daffodils usually come back reliably. There are several things that might be going on. First, the bulb season has a long way to go if you're in zone 5. If the daffodils are a mix, some may bloom later than others and just haven't thrown their buds yet.

If that's not the case, the previous owners could have cut the foliage down too early last spring, preventing the bulbs from recharging their food stores for this year's bloom. If they are situated in heavy shade, that can also reduce bloom.

Or the daffodils might be too crowded to bloom. If you get a huge clump of foliage but few or no blooms, that's the problem. Dig them up, separate and replant.

Good luck!

Bulbs don't produce flowers for a reason:
Possibles.......the bulb does not have sufficient energy to proceed to flower stage due to 1. a severe winter caused the bulbs to erupt from freeze/thaw cycles
2. possible foliage came up too soon in mild winter intervals and foliage paid the price of freezes that followed
3. you did not allow sufficient time for the foliage to die back--to send the starches and sugars back down into the bulb which is how the bulb reproduces its bloom.
you cut back the foliage too soon.
4. perhaps there was not sufficient sunlight the previous summer
5. perhaps you overfed them....perhaps the bulb garden area is close to your lawn and you fed nitrogen to the lawn area and its effects spilled over into the bulbs causing great volume sof foliage---but denied bloom.
(nitrogen can do that---it causes foliage to do well at the expense of flowers)
6. perhaps you allowed too much water to soak the bulb area causing them to sit too long in soggy ground
this causes the bulb to take up too much moisture and possibly begins rotting in inside the bulb.
7. perhaps you tied up the foliage---wanting to hide the browning--thiss too can affect how much sugars are sent down into the bulb
8. disease....the ground may have been invaded by something that has caused the bulb to stop producing
9. pests....perhaps a squirrel got into the chicken house and started nibbling...
they usually will not eat a daffodil bulb and this is why sometimes it is suggested to plant daffs amongst tulips.
But a pest only needs to possibly upset a bulb, knock it out of its position, possibly turning it over--which can cause the bulb to not come up as usual.
Sometimes too, a bulb, lying on its side, will still send up foliage but be prevented from producing a flower as old.

Sometimes too a too-wet spring will delay bulbs from coming up as soon as they usually do---you could dig up one or two and see if anything untoward has happened--then re-lant them and give it more time.

Thank you everyone!
Jeannie7, we purchased the house in January, so I have no idea what they did the previous summer. I wouldn't be surprised if squirrels or deer go to them though. We have very poor drainage, and it sounds like that could also be a problem.

Thanks!