This depends on 1) the type of bulbs you have and 2) where you put them.
* If you have "landscape" or "naturalizing" bulbs, or any of the native species, they are likely to spread. They tend to have fairly basic colors and shapes, but are vigorous.
* If you have fancy bulbs, then few of them are prone to spreading and they rarely last more a season or few. However, they have more dramatic colors and shapes.
* If you put bulbs in a confined bed with rigid borders, they are more likely to overrun it. They can't get out except by seeding and they have little or no competition.
* If you put bulbs in a yard or a bed that is only defined by a grass edge, they are less likely to become crowded. They have room to move and they also have competition from other plants.
I have naturalized daffodils that have been in place for decades with no problem. I also had to dig out the confined bed because last spring it was more leaves than flowers. I probably pulled hundred of little bulblets out of there, and left the biggest ones in hope of getting some flowers. The extras I distributed around the yard in other places.
To determine what you have in a new house, you can:
1) Observe the flowers in spring and compare them to things in a bulb catalog to see if they look more like the fancy or plain bulbs there.
2) If you see lots of leaves but few flowers, the bed would probably benefit from division.
3) Or you can just wait until they quit flowering, then do a bit of test digging to see if the bed is crowded or not.
Thoughts
* If you have "landscape" or "naturalizing" bulbs, or any of the native species, they are likely to spread. They tend to have fairly basic colors and shapes, but are vigorous.
* If you have fancy bulbs, then few of them are prone to spreading and they rarely last more a season or few. However, they have more dramatic colors and shapes.
* If you put bulbs in a confined bed with rigid borders, they are more likely to overrun it. They can't get out except by seeding and they have little or no competition.
* If you put bulbs in a yard or a bed that is only defined by a grass edge, they are less likely to become crowded. They have room to move and they also have competition from other plants.
I have naturalized daffodils that have been in place for decades with no problem. I also had to dig out the confined bed because last spring it was more leaves than flowers. I probably pulled hundred of little bulblets out of there, and left the biggest ones in hope of getting some flowers. The extras I distributed around the yard in other places.
To determine what you have in a new house, you can:
1) Observe the flowers in spring and compare them to things in a bulb catalog to see if they look more like the fancy or plain bulbs there.
2) If you see lots of leaves but few flowers, the bed would probably benefit from division.
3) Or you can just wait until they quit flowering, then do a bit of test digging to see if the bed is crowded or not.
https://www.thespruce.com/is-it-necessary-to-divide-spring-bulbs-1402236