a psychologist in to look at it. This prompts George to say,

What would a psychologist want with a nursery?

Lydia pushes back by saying he knows why—the nursery is acting strangely, just as a person with a problem might.

Other individual features of the house are personified. The stove is "humming" to itself as it makes dinner, as a person might. Lydia notes that the house has taken over the parental duties of raising the children so that it

is wife and mother now, and nursemaid.

The nursery seems especially malevolent and like an evil person to the Hadley parents. While George Hadley tries to reassure his wife that the images on its view screens are simply what we would call pixels, he has to admit that there seems to be a humanlike emotionality of hate driving it. When the psychologist, Mr. McClean comes, he describes the nursery as emanating "hatred."

Bradbury personifies the house to show how technology can grow out of control and take over our lives like a tyrant if we don't manage it properly.

Personification—or the attribution of human characteristics to non-human entities—is largely used within Ray Bradbury's short story "The Veldt" in order to provide a sinister tone to the events which take place within the "HappyLife Home" that has been purchased by the Hadley family.

The other educator who responded to this question has done quite a thorough job of outlining instances of personification within the story, but I will elaborate in order to provide more context.

After Lydia and George first encounter the lions voraciously feeding on a dead animal in the the African "veldt" that has been manifested by the nursery, the couple is faced with the problem of dealing with their children's obsession with the room. Lydia has begun to regret purchasing the house, which in meeting her initial desires of relieving her of parental duties has also rendered her useless to her children, as she vocalizes by saying,

That's just it. I feel like I don't belong here. The house is wife and mother now, and nurse for the children. 

The personification of the house as having assumed the marital and motherly responsibilities is quite disturbing, and foreshadows the couple's later demise.

After Lydia and George discover the children are disobeying their orders to stay away from the nursery, it is noted that:

Although their beds tried very hard, the two adults couldn't be rocked to sleep for another hour.

Again, we are given a sense of artificial, human-like comfort being provided by the house.

A psychologist who comes to assist George and Lydia decides the couple spoils their children, which has resulted in resentment now that nursery access has been blocked. When observing the room, he states,

No wonder there's hatred here. You can feel it coming out of the sky. Feel that sun. 

The house i no longer just acting. It is also feeling and expressing emotions.

The sense that the house is a living thing is once again reaffirmed when Peter begins screaming,

"Don't let them do it!" cried Peter to the ceiling, as if he was talking to the house, the nursery. "Don't let Father kill everything."

The children clearly regard the house as a living, breathing entity, and the suggestion that to power it down would be to "kill it" only makes that concept more alarming. Ultimately, this sense of agency is manifested when the lions projected by the house kill the parents.

Personification is a figure of speech used to give inanimate objects living or human characteristics.  Ray Bradbury is a master of using figures of speech in his very descriptive writing. 

Here are a few examples I found.  Most of them have to do with personifying the house and bringing it to life.

“. . . this house which clothed and fed and rocked them to sleep and played and sang and was good to them.”  Here the house is being compared to a mother taking care of her children.

“ . . . the walls began to purr and recede into crystalline distance.”

“The house is wife and mother now, and nursemaid.”

“The room is their mother and father, far more important in their lives than their real parents.”

“George Hadley walked through the singing glade and picked up something that lay in the corner near where the lions had been.”  The singing glade is an example of personification because of the human characteristic Bradbury is giving the grass or glade.

“And the whole damn house dies as of here and now.”

Personification is a literary device in which a thing, animal, or inanimate object is given human attributes in order to add an aesthetic quality to the narrative and contribute to the author's description. Ray Bradbury continually personifies George and Lydia Hadley's Happylife Home throughout his celebrated short story "The Veldt." The Happylife Home is a completely automated, technologically advanced smart home which performs everyday functions. The home cooks, cleans, bathes, and entertains the Hadley family. Unfortunately, the Hadleys have become over-reliant on technology, and the Happylife Home begins to replace George and Lydia as parents. Lydia expresses her displeasure and personifies the home by saying,

The house is wife and mother now, and nursemaid.

By personifying the house as wife, mother, and nursemaid, Lydia is implying that the house functions as a caring, helpful member of their family. Another example of personification takes place when Bradbury writes,

George Hadley walked through the singing glade and picked up something that lay in the corner near where the lions had been.

The glade is personified and given the human attribute of speech when Bradbury writes that it is "singing." This use of personification influences the reader to view the glade as a peaceful, lively setting. Another example of personification takes place when Bradbury writes,

And although their beds tried very hard, the two adults couldn’t be rocked to sleep for another hour.

The beds are personified and given the human attribute of effort when they try "very hard" to rock the adults to sleep. Overall, Bradbury's use of personification contributes to the description of the automated Happylife Home, which completely replaces George and Lydia as parents.

The technologically advanced Happylife Home seems to function as a person because of all it does for the family. Some images of personification, or describing the house as if it is a person, are the following:

[the house] clothed and fed and rocked them to sleep and played and sang and was good to them.

This implies the house is like a nanny or parent to the family, even the adults. It also implies that the house infantilizes them.

Lydia herself personifies the house when she says to George,

"The house is wife and mother now, and nursemaid."

George speaks to the dining room table, and it responds as if it is a person:

“We forgot the ketchup,” he [George] said.

“Sorry,” said a small voice within the table, and ketchup appeared.

When Mr. McClean, the psychologist, comes, he also speaks of the nursery as if it is a person:

This room is their mother and father, far more important in their lives than their real parents.

When he and Mr. Hadley switch off the nursery, they "threw the switch that killed the nursery." "Killed" implies that the nursery can die like a human being.

Throughout the story, we see both a soulless piece of technology functioning as a human being and the characters in the story treating it, and thinking about it, as if it were human. Unfortunately, however, the house is only programmed to respond to what the occupants want and to try to deliver that. It is incapable of making moral evaluations about what might be good for the family, especially the children.

Some other lines in Ray Bradbury's "The Veldt" that personify the Happylife Home operating system occur after the psychologist visits the Hadley home and George Hadley decides to turn off the system. Bradbury writes, "The house was full of dead bodies, it seemed. It felt like a mechanical cemetery." In this line, Bradbury compares switching off the system to actually killing sentient beings. The inert Happylife system is not simply a machine at rest; instead, it is dead and buried in a cemetery, as if it were once alive. Peter and Wendy are incredibly distraught after their father has taken away the play object that has become their parents, and Peter begs his parents, "Don't let Father kill everything." Peter's use of the word "kill" also personifies the Happylife system, as it suggests that it was once living and is more real to the children than their actual parents, who have let the system raise and care for their children. 

Two different passages that contain personification as it relates to the Happylife Home are the following:

1. They walked down the hall of their soundproofed Happylife Home, ...this house which clothed and fed and rocked them to sleep and played and sang and was good to them.
2. "...the whole damn house dies as of here and now"

In the second example, Peter's father thinks of the house as alive because he says, "...the whole damn house dies as of here and now" as he shuts off various machines throughout the house, as well as the nursery.

This use of personification by Bradbury underscores his theme of the dangers of technology. By becoming too dependent upon machinery and other non-human sources, man risks becoming alienated from others. And, certainly, too much attention to technology mitigates emotional involvement with others.

The Happylife Home System apologizes to George Hadley when it forgets to put ketchup on the dinner table: "'Sorry,' said a small voice within the table, and ketchup appeared." At first, the home system seems pleasant, accommodating, and committed to pleasing the family.

After George Hadley shuts off the Happylife system because of the malfunction in the nursery and his children's increasing willfulness, he notes that "the house was full of dead bodies, it seemed. It felt like a mechanical cemetery. So silent."

Bradbury's narrator implies that the mechanized home has acquired self-awareness and that the Hadley children are able to communicate with it in a way their parents are unable to. The children develop a relationship with the Happylife system that enables them to override their parents' decisions with regard to the nursery environment. In the end, the children and the system prevail, and the parents, who have become the enemy of the system, are eliminated.

The story begins with George Hadley and his wife discussing sending a psychologist, not a technician, to look at the Happylife Home system. So right away, Ray Bradbury sets up the idea that this Happylife Home system is more than just a computerized nursery. Bradbury suggests that this nursery has a mind that needs a psychologist to look at.

When the Hadleys do call a psychologist, he discusses the nursery as if it was a person as it had "the usual violences, a tendency toward a slight paranoia here or there..."

In addition, the psychologist calls the room the children's "mother and father, far more important in their lives than their real parents."

When the Hadleys shut off the Happylife Home, George says, "...the whole damn house dies as of here and now." This comparison of shutting off something electronic to humans doesn't end there. The narrator says, "The house was full of dead bodies, it seemed. It felt like a mechanical cemetery."