Sleep Science
While there are many daytime abduction experiences, the majority reported still happen at night. Some of these nightime abductions (or indeed daylight nap time abductions) might be what I like to call "Spooky Sleep". A sleep problem is a far more manageable problem then aliens! It's good to check with your doctor if you think you are having any of these "Spooky Sleep" symtoms.
PARASOMNIA
"Parasomnia" simply means "faulty sleep". Parasomnias tend to run in families, which may explain why abduction experiences also tend to run in families. Parasomnias include sleep walking, sleep eating (yes people have eaten all sorts of weird stuff while sleeping, one symptom, unexplained weight gain), somniloquy (talking in your sleep), and night sweats. The point is that a parasomnia can explain bruises and cuts you don't remember getting. You brain can do a lot while you are asleep, so if your pantry is empty and your waistline expending....don't blame the aliens, it could be YOU.
NIGHT TERRORS
Night terrors aren't nightmares. It's when a person gets caught between sleep stages. A person awakes terrified with an increased heart rate. You might remember a night terror, but many people have little memory of it. However, family members may blame a night terror on aliens. Historically demons, succubus, vampire, ghosts have all been blames for causing night terrors. Science can't explain why night terrors happen, so if the blame is aliens or simply that sleep can sometimes be spooky, you have to make up your own mind.
HYPNOGOGIC HALLUCINATIONS
Often when a skeptic talks about alien abductions they will mention "hypagogic " or "hynopompic" hallucinations. Hypagogic refers to a halluciation that happens when you are falling asleep. Hynpompic refers to when you are waking up. Unlike night terrors people tend to remember a hypnogogic hallucination. Sometimes the hallucination isn't frightening. Sometimes it is. But no matter what the halucination feels very real. People tend to hallucinate about what they know. If you are very religious, you will tend to "see" an angel or demon. Aliens tend to look like whatever films or books you are familiar with, little grays being popular now. In the 1950s a beautiful Venusian would be more likely to visit. There is often a feeling of being crushed or unable to move. Once again, science is unsure of the cause, but this is a well known sleep problem. If combined with sleep paralysis it can be very frightening.
Narcolepsy
Some skeptics think that some daytime "alien abduction" experiences are really daytime hynogogic hallucinations. People unaware they suffer from a mild form of nacrolepsy (simply put, the inability to control your sleep/wake cycle) can have hallucinations in the daytime unaware that they have a from of nacrolepsy. For safety this should always be checked out by a doctor!
SLEEP PARALYSIS
Sleep paralysis is something that happens to everyone that sleeps! We usually aren't even aware of this protective measure our brain uses to keep us in bed and from hurting ourselves during the the part of sleep where we enter the REM (rapid eye movement) stage. A person is unable to move, and even speaking can be a problem. Sometimes people feel they are floating. Added to a hypnogogic hallucination and you have a really spooky sleep experinece. But sleep paralysis is simply how our minds keep us safe!