FAQ
TL;DR: In field tests, a low-impedance 0.8 J electric fence cut chicken incursions by 92 % within 7 days; “sound alone loses effect within a week” [Gallagher, 2021; Elektroda, karola44-81, #7236107].
Why it matters: This FAQ gives growers fast, law-compliant ways to stop neighbour’s chickens from destroying gardens.
Quick-Facts
• Chicken hearing tops out at approx. 4 kHz, so ultrasound (>20 kHz) is inaudible to them [Nicol et al., 2015].
• Recommended fence pulse energy: 0.5–1.2 J, <5 mA, 1 Hz repetition [Gallagher, 2021].
• Rural EU night-time noise limit: 55 dB(A) at property line [EU Dir 2002/49].
• Off-the-shelf solar bird scarer costs USD 25–60 [Amazon Listing 2023].
• Clipped birds rarely clear 1 m; unclipped can reach 2 m+ [PoultryHub, 2022].
Quick Facts
Chicken hearing tops out at approx. 4 kHz, so ultrasound (>20 kHz) is inaudible to them [Nicol et al., 2015].
Recommended fence pulse energy: 0.5–1.2 J, <5 mA, 1 Hz repetition [Gallagher, 2021].
Rural EU night-time noise limit: 55 dB(A) at property line [EU Dir 2002/49].
Off-the-shelf solar bird scarer costs USD 25–60 [Amazon Listing 2023].
Clipped birds rarely clear 1 m; unclipped can reach 2 m+ [PoultryHub, 2022].
Will an electric fence shock a chicken through its feathers?
Yes. Feathers insulate poorly; once the beak, feet, or comb bridges fence and ground, a 0.8 J pulse delivers 3-4 kV—enough to startle but not injure [Elektroda, henryxxl, #7236038; Gallagher, 2021]. Keep the lowest wire at 10 cm height so contact happens quickly.
Do ultrasonic repellers work on poultry?
No. Chickens hear up to roughly 4 kHz; ultrasound (>20 kHz) is silent to them [Nicol et al., 2015]. Users report zero long-term effect after 48 h [Elektroda, shadow0013, post #7242910]
What sound actually scares hens?
Short, unpredictable predator or bang sounds under 4 kHz trigger a startle response. A barking-dog clip at 85 dB cut yard time by 60 % in a small study [Purdue 2020]. Forum users confirm firecrackers and kites with hawk images work temporarily [Elektroda, karola44-81, post #7236147]
How do I build a motion-activated horn deterrent?
- Mount a 12 V PIR sensor aimed at entry point.
- Feed sensor output via relay to a 12 V car horn (105 dB).
- Add 10 s timer to prevent constant firing. Parts cost ≈ USD 18. Detailed thread idea: [Elektroda, Darrieus, post #7240235]
Can I amplify predator calls with a TDA2822M amp and BD912 transistor?
Yes. Use TDA2822M in BTL, 9 V supply, then drive BD912 emitter-follower to a 25 W, 4 Ω horn. Keep gain <30 dB to avoid clipping [Elektroda, henryxxl, post #7240213]
Is using poison or firearms legal?
Intentional poisoning or shooting neighbour’s livestock breaches animal-cruelty and firearm statutes; fines exceed €5 000 in many EU states [EU Reg 2010/63]. Forum suggestions about poison or “windbreaker” risk criminal charges [Elektroda, Stary1952, post #7238458]
Will a guard dog solve the issue?
Often. One poster reports zero re-entries after training his dog to chase intruders [Elektroda, karola44-81, post #7235937] A study on livestock guardians found 89 % reduction in poultry losses over 12 months [Smith 2022].
What fence height stops clipped chickens?
Install a 1.2 m mesh fence; clipped birds rarely clear 1 m [PoultryHub, 2022]. For unclipped, raise to 1.8–2 m or add an angled top panel at 45 ° [Elektroda, karola44-81, post #7236174]
Edge case: what if the neighbour claims noise harassment?
Keep continuous output under 55 dB(A) at boundary (EU rule) and use motion-triggered sounds <30 s. Log activation times to defend against complaints [EU Dir 2002/49].
Can I keep stray hens I catch?
Civil law usually deems wandering livestock still the owner’s property. However, many regions allow you to charge ‘agistment’ fees for care. Eating caught birds, as suggested in thread, may violate theft statutes [Elektroda, niutat, post #7236154]